Are you sure you didn't get help files with advanced terrain? Attached is a screen shot of what my help files look like. They are not actually viewed through DBP like most help files. I actually found them under: all programs>the game creators>advanced terrain expansion pack>advanced terrain help.
Just in case you can't find them, here is a piece of code in which I put remarks (copied from the example) about the advanced terrain commands. I used this piece of my own code instead of the example because it doesn't use media.
The terrain commands are around line 100.
sync on
sync rate 60
hide mouse
autocam off
randomize timer()
print "Loading..."
sync
sync
set camera range 0.01,100
color backdrop rgb(0,150,250)
width=256
height=256
make memblock 1,width*height*32*4+12
write memblock dword 1,0,width
write memblock dword 1,4,height
write memblock dword 1,8,32
for x=0 to width-1
for y=0 to height-1
c=rnd(255)
write memblock dword 1,(y*width+x)*4+12,rgb(c,c,c)
next y
next x
make memblock 2,width*height*32*4+12
write memblock dword 2,0,width
write memblock dword 2,4,height
write memblock dword 2,8,32
for smooth=1 to 10
blur(width,height)
next smooth
make image from memblock 1,1
save image "map.bmp",1
delete image 1
for x=0 to width-1
for y=0 to height-1
c=rnd(255)
write memblock dword 1,(y*width+x)*4+12,rgb(rnd(c*.80),c,rnd(c/2))
next y
next x
for smooth=1 to 2
blur(width,height)
next smooth
make image from memblock 1,1
for x=0 to width-1
for y=0 to height-1
c=rnd(10)+120
write memblock dword 1,(y*width+x)*4+12,rgb(c,c,c)
next y
next x
make image from memblock 2,1
for x=0 to width-1
for y=0 to height-1
write memblock dword 1,(y*width+x)*4+12,rgb(255,255,255)
if rnd(3)=0
write memblock byte 1,(y*width+x)*4+15,rnd(255)
else
write memblock byte 1,(y*width+x)*4+15,0
endif
next y
next x
for smooth=1 to 5
blur(width,height)
next smooth
make image from memblock 3,1
delete memblock 1
delete memblock 2
make memblock 2,10*10*32*4+12
write memblock dword 2,0,1
write memblock dword 2,4,8
write memblock dword 2,8,32
for x=0 to 9
for y=0 to 9
write memblock dword 2,(y*10+x)*4+12,rgb(0,150,255)
next y
next x
make image from memblock 4,2
delete memblock 2
make memblock 1,12+(36*225*6)
write memblock dword 1,0,338
write memblock dword 1,4,36
write memblock dword 1,8,225*6
for x=0 to 14
for z=0 to 14
create_vertex(1,v,x*51.25,0,z*51.25,rgb(255,255,255),0,0)
create_vertex(1,v+1,x*51.25,0,(z+1)*51.25,rgb(255,255,255),0,1)
create_vertex(1,v+2,(x+1)*51.25,0,z*51.25,rgb(255,255,255),1,0)
create_vertex(1,v+3,(x+1)*51.25,0,z*51.25,rgb(255,255,255),1,0)
create_vertex(1,v+4,x*51.25,0,(z+1)*51.25,rgb(255,255,255),0,1)
create_vertex(1,v+5,(x+1)*51.25,0,(z+1)*51.25,rgb(255,255,255),1,1)
inc v,6
next x
next z
make mesh from memblock 1,1
make object 5,1,4
set object light 5,0
set alpha mapping on 5,50
position object 5,0,70,0
`These are the important commands for making the terrain-
` create the terrain object
make object terrain 1
` set the heightmap
set terrain heightmap 1, "map.bmp"
` set the scale
set terrain scale 1, 3, 0.6, 3
` split value by 16 * 16
set terrain split 1, 16
` detail map tiling
set terrain tiling 1, 4
` light - xdir, ydir, zdir, red, green, blue, intensity
set terrain light 1, 1, -0.25, 0, 1, 1, 0.78, 0.5
` base and detail texture
set terrain texture 1, 1, 2
` finally build the terrain
build terrain 1
for i=2 to 3
make object plain i,768,768,1
xrotate object i,90
texture object i,3
set object transparency i,1
next i
position object 2,384,90,384
position object 3,384,88,384
yrotate object 3,-90
make object sphere 4,-200
set object light 4,0
texture object 4,3
set object transparency 4,1
position camera 384,0,384
do
sync
move(0,0.05)
scroll object texture 2,0.0001,0.0001
scroll object texture 3,0.0003,0.0005
position object 4,camera position x(),camera position y(),camera position z()
v=0
t=timer()/100.0
wavefrequency=20000
for x=0 to 14
for z=0 to 14
position_vertex(1,v,x*51.25,(sin(t+x*wavefrequency)+cos(t+z*wavefrequency))*2,z*51.25)
position_vertex(1,v+1,x*51.25,(sin(t+x*wavefrequency)+cos(t+(z+1)*wavefrequency))*2,(z+1)*51.25)
position_vertex(1,v+2,(x+1)*51.25,(sin(t+(x+1)*wavefrequency)+cos(t+z*wavefrequency))*2,z*51.25)
position_vertex(1,v+3,(x+1)*51.25,(sin(t+(x+1)*wavefrequency)+cos(t+z*wavefrequency))*2,z*51.25)
position_vertex(1,v+4,x*51.25,(sin(t+x*wavefrequency)+cos(t+(z+1)*wavefrequency))*2,(z+1)*51.25)
position_vertex(1,v+5,(x+1)*51.25,(sin(t+(x+1)*wavefrequency)+cos(t+(z+1)*wavefrequency))*2,(z+1)*51.25)
inc v,6
next z
next x
make mesh from memblock 1,1
delete object 5
make object 5,1,4
set object light 5,0
set alpha mapping on 5,50
position object 5,0,70,0
loop
delete file "map.bmp"
end
function move(cam,speed#)
rotate camera cam,restrict(camera angle x(cam)+mousemovey()/2.0,-90,90),camera angle y(cam)+mousemovex()/2.0,0
angy#=camera angle y(cam)
forward=upkey()-downkey()
side=rightkey()-leftkey()
position camera camera position x(cam)+(cos(angy#)*side+sin(angy#)*forward)*speed#,get terrain ground height(1,camera position x(cam)+(cos(angy#)*side+sin(angy#)*forward)*speed#,camera position z(cam)+(cos(angy#)*forward-sin(angy#)*side)*speed#)+0.1,camera position z(cam)+(cos(angy#)*forward-sin(angy#)*side)*speed#
endfunction
function blur(width,height)
for x=0 to width-1
for y=0 to height-1
max=((height-1)*width+width-1)
r=memblock byte(1,restrict((y*width+x),0,max)*4+14)*.3+memblock byte(1,restrict((y*width+x-1),0,max)*4+14)*.15+memblock byte(1,restrict((y*width+x+1),0,max)*4+14)*.15+memblock byte(1,restrict(((y-1)*width+x),0,max)*4+14)*.15+memblock byte(1,restrict(((y+1)*width+x),0,max)*4+14)*.15+memblock byte(1,restrict(((y-1)*width+x-1),0,max)*4+14)*.025+memblock byte(1,restrict(((y-1)*width+x+1),0,max)*4+14)*.025+memblock byte(1,restrict(((y+1)*width+x-1),0,max)*4+14)*.025+memblock byte(1,restrict(((y+1)*width+x+1),0,max)*4+14)*.025
g=memblock byte(1,restrict((y*width+x),0,max)*4+13)*.3+memblock byte(1,restrict((y*width+x-1),0,max)*4+13)*.15+memblock byte(1,restrict((y*width+x+1),0,max)*4+13)*.15+memblock byte(1,restrict(((y-1)*width+x),0,max)*4+13)*.15+memblock byte(1,restrict(((y+1)*width+x),0,max)*4+13)*.15+memblock byte(1,restrict(((y-1)*width+x-1),0,max)*4+13)*.025+memblock byte(1,restrict(((y-1)*width+x+1),0,max)*4+13)*.025+memblock byte(1,restrict(((y+1)*width+x-1),0,max)*4+13)*.025+memblock byte(1,restrict(((y+1)*width+x+1),0,max)*4+13)*.025
b=memblock byte(1,restrict((y*width+x),0,max)*4+12)*.3+memblock byte(1,restrict((y*width+x-1),0,max)*4+12)*.15+memblock byte(1,restrict((y*width+x+1),0,max)*4+12)*.15+memblock byte(1,restrict(((y-1)*width+x),0,max)*4+12)*.15+memblock byte(1,restrict(((y+1)*width+x),0,max)*4+12)*.15+memblock byte(1,restrict(((y-1)*width+x-1),0,max)*4+12)*.025+memblock byte(1,restrict(((y-1)*width+x+1),0,max)*4+12)*.025+memblock byte(1,restrict(((y+1)*width+x-1),0,max)*4+12)*.025+memblock byte(1,restrict(((y+1)*width+x+1),0,max)*4+12)*.025
a=memblock byte(1,restrict((y*width+x),0,max)*4+15)*.3+memblock byte(1,restrict((y*width+x-1),0,max)*4+15)*.15+memblock byte(1,restrict((y*width+x+1),0,max)*4+15)*.15+memblock byte(1,restrict(((y-1)*width+x),0,max)*4+15)*.15+memblock byte(1,restrict(((y+1)*width+x),0,max)*4+15)*.15+memblock byte(1,restrict(((y-1)*width+x-1),0,max)*4+15)*.025+memblock byte(1,restrict(((y-1)*width+x+1),0,max)*4+15)*.025+memblock byte(1,restrict(((y+1)*width+x-1),0,max)*4+15)*.025+memblock byte(1,restrict(((y+1)*width+x+1),0,max)*4+15)*.025
write memblock dword 2,(y*width+x)*4+12,rgb(r,g,b)
write memblock byte 2,(y*width+x)*4+15,a
next y
next x
for x=0 to width-1
for y=0 to height-1
write memblock dword 1,(y*width+x)*4+12,memblock dword(2,(y*width+x)*4+12)
write memblock byte 1,(y*width+x)*4+15,memblock byte(2,(y*width+x)*4+15)
next y
next x
endfunction
function restrict(value,min,max)
if value<min
value=min
endif
if value>max
value=max
endif
endfunction value
function create_vertex(memnum,v,vposx#,vposy#,vposz#,color as dword,u#,v#)
write memblock float memnum,v*36+12,vposx#
write memblock float memnum,v*36+16,vposy#
write memblock float memnum,v*36+20,vposz#
write memblock dword memnum,v*36+36,color
write memblock float memnum,v*36+40,u#
write memblock float memnum,v*36+44,v#
endfunction
function position_vertex(memnum,v,vposx#,vposy#,vposz#)
write memblock float memnum,v*36+12,vposx#
write memblock float memnum,v*36+16,vposy#
write memblock float memnum,v*36+20,vposz#
endfunction
