Try this:
Code:

---

var force_vector[3];
function physics_hit()
{	
        if (event_type == event_impact)&&(you.skill1 == 4)
	{	          	
           force_vector.x = you.skill8*10;	
           force_vector.y = 0;	
           force_vector.z = 0;	
           vec_rotate(force_vector, you.pan);
           phent_addforcelocal (my, force_vector, you.x);	
        }
}

---

Maybe you could use phent_addcentralforce(my, vector_force) to apply a linear force in the entity´s center of mass.