Well if you write a clean small code then it's no rocket science, as I said. Just make sure to use the "did I already pass by the next waypoint? If so, increment waypoint counter!" method. BTW you may also combine this simple move-towards-nextwaypoint (without exact interpolation) with a realtime controlled thing for the idle phases. Shouldn't be that hard, simply calc the idle time between the first and last waypoint of the same position.