If you are trying to strafe the camera (move it sideways while you are looking in one direction) then you have to calculate the new position based on 90 degrees to the current y angle the camera is facing.
So if you want to move the camera 5 units left or right for example:
autocam off
make matrix 1,1000,1000,25,25
x#=500
y#=20
z#=500
position camera x#,y#,z#
do
lefty#=wrapvalue(camera angle y()-90)
righty#=wrapvalue(camera angle y()+90)
if rightkey()=1
x#=newxvalue(x#,righty#,5)
z#=newzvalue(z#,righty#,5)
endif
if leftkey()=1
x#=newxvalue(x#,lefty#,5)
z#=newzvalue(z#,lefty#,5)
endif
position camera x#,y#,z#
loopEnjoy your day.
