You need to enable mouse engine pointer "mouse_mode = 1",
then sync the mouse_pos with mouse_cursor :

Code:

---

function mouse_test()
{
   mouse_mode = 1;
   mouse_range = 2000; // if necessary
   while(1)
   {
      mouse_pos.x = mouse_cursor.x;
      mouse_pos.y = mouse_cursor.y;

      temp.x = MOUSE_POS.x;
      temp.y = MOUSE_POS.y;
      temp.z = 9999.99;
      vec_for_screen(temp, camera);
      wait(1);
   }
}