Did you try the Controls in my capx? You can use it while the waypoing stays the target already.
The difference is to use the object as the waypoint target, instead of waypoint.x . Once stopped, move a temporary waypoint to the Players position, and set it as new waypoint. So the old target is overwritten.
All right? Here is a simple solution without using rex's behavior, but simulated Keydowns.
[attachment=0:39fvgcdm][/attachment:39fvgcdm]
Hope it helps.