Thanks for the help. This was my modified implementation. It's not quite correct yet. See anything wrong?

//DEBUGGING SLIDE
if (key_cul == on)
{
my.skill3 = time * player_speed.pan + max (1 - time * 0.3, 0) * my.skill3;
temp = my.skill3 * time;
my.pan += temp;
vec_rotate(player_speed.x, vector(-temp,0,0));
vec_set(temp.x, player_speed.x);
vec_scale(temp.x, time);
ent_move(temp.x, nullvector);
}