enhancing all that...
Code:

---

define spot_track, skill51;
define target, skill1;

function spot(ent)
{
  if (ent == null) {
    my.spot_track = 0;
    my.target = null;
    return;
  }

  my.target = handle(ent);
  my.spot_track ++;

  while (my.spot_track == 1) {
    if (my.target != null) {
      you = ptr_for_handle(my.target);
      vec_set(temp.x, you.x);
      vec_sub(temp.x, my.x);
      vec_to_angle(my.pan, temp.x);
    }
    wait(1);
  }
}

---

haven't tested that, though i think you get the idea of comfort you have with such little functions. so instead of requesting an "engine" feature, you should rather think over your problem once more.

joey.