Well, you should read the manual, but with that said, I just wanted to post an example of code:
camera.z += (0.5 * mickey.z); //allow the camera to zoom in on middle mouse
if(camera.z < 1500) camera.z = 1500; //don't exceed bounds
if(camera.z > 4000) camera.z = 4000; //don't exceed bounds
wait(1); //avoid endless loops
It works like mouse_force and key_force.
