all right, I had to get home to do the explanation for you. here is a code example.
set display mode 800,600,32
sync on : sync rate 60
autocam off
position camera 0,0,0,-200
make object box 1,20,40,20 : position object 1,50,0,0
make object box 2,20,40,20 : position object 2,-50,0,0
make object sphere 3,10 : position object 3,0,0,200
lock object on 3
do
print "use right/left/up/down arrow keys to control camera"
print "use use W / S keys to move the ball up and down"
print "the result:"
print "we stop the object from rendering to the camera and it looks as stand still on the camera screen"
print "this is very usefull effect to get a rid of some mathematics.
print "remember that the object does not loose its specification;"
print "all object commands are still applied to it."
control camera using arrowkeys 0,1,1
move object 3,(inkey$()="w")-(inkey$()="s")
sync
LOOP
now, the command "lock object on objno" does not actually keep the object (in the example sphere) at relative position from the camera but, it stick the object on the screen and it looks as moving with the camera.
if you're looking for more complicated position/rotation calculations, I suggest using EZ rotate. it's such an amazing pluggin and I used it for major delivered projects.
http://www.thegamecreators.com/?m=view_product&id=2082