just some simple things to try...

camera.tilt += mouse_force.y; this won't' make the camera look at the player, but only change the camera tilt,
change this to at the least
then where you apply the view potision, change the 50 to height
vec_set(-180, 0, height);
oh and obviously declare your height var as 50 at the start with too
then have it look back at the player
vec_set(temp,your.x);
vec_sub(temp,my.x);
vec_to_angle(my.pan,temp);
this has a good chance of not working at all, but the basic principals are there what you need
you may also want to add so when the mouse_force.y increase, the camera also gets closer
Hope this helps
at least a little
