Agree with Schulzs. The foal needs to learn to be sent with pressure, like a casual circle. Pull and direct with the directional hand, and apply pressure by spinning the end of the rope. If he doesn't move, you get closer with the rope and tap his shoulder until he moves off. If he dives into you, pop him with the rope underhand on his belly.
Then, once he walks around you calmly in a circle, pull his head and step towards his butt and make him relinquish his hindquarters.
Just teaching my 4 month old this technique this week. :)