Not tried, but at first glance, I wouldn't expect it to work.
Wouldn't you have to use something like:
MM=mousemovex() : yrotate camera WrapValue(Camera Angle Y()+MM)
Just a guess this time...
[Edit] Nearly right first time...
Sync On
CLS 0
Hide Mouse
Make Matrix 1,500,500,20,20
Make Object Cube 1,3
Position Object 1,250,3,250
Position Camera 250,10,240
Point Camera 250,3,250
XDist#=20.0: YDist#=20.0: ZDist#=20.0
Do
MM = mousemovex()
X# = WrapValue(X# + MM)
Z# = WrapValue(Z# + MM)
Position camera newxvalue(Object Position X(1),X#,XDist#),newyvalue(Object Position Y(1)+5,10.0,0),newzvalue(Object Position Z(1),Z#,ZDist#)
Move Object 1,.1
Point Camera Object Position X(1),Object Position Y(1),Object Position Z(1)
Sync
Loop
TDK_Man