Do you mean you want to control the tilt manually while the pan always looks at a target?
If so, here is a quick example using the mouse to manually control the tilt:
Code:

---

  

var tilt_ang;
 
while(me)
{ 
  vec_set(temp,vecTarget.x);
  vec_sub(temp,my.x);
  vec_to_angle(my.pan,temp); 
  
  my.tilt = 0;
  tilt_ang += (mouse_force.y * 3) * time_step;
  tilt_ang = clamp(tilt_ang, -80, 80); //clamp tilt between 80 and -80 degrees
  my.tilt += tilt_ang;
  
  wait(1);
}

---

You might also want to set the roll to 0 when you set the tilt to 0, or your "my" will roll.