Mappoint 2006 --> how to set start/end/stop point

hello boys,
how can i set the start/end/stop time?

wRoute.Waypoints.Add( wMap.FindResults("FistCity").get_Item(ref item) , "Milano");
wRoute.Waypoints.Add(wMap.FindResults("SecondCity").get_Item(ref item), "Lecco");
wRoute.Waypoints.Add(wMap.FindResults("thirdCity").get_Item(ref item), "Roma");

I've readden that there is a propriety Type, but i can only read this.
so.. how can i set it?
thanks