@0-markymark-0 this is the util i was on about
http://www.tcxconverter.com/TCX_Converter/TCX_Converter_ENG.html it writes direct to the unit (well the ones I have had), also its possible with it to create a history file from a course by putting in an average speed, and export as a history file which might be a way round your problem, create the route in rwgps import into tcx converter save as history file put in your history folder (or whatever its called) do ride from history, I can see that missing the waypoints a true course file has though, just be careful with any autosyncs as it might be seen as a new ride, again another reason I prefer doing somethings manually.
also useful for strava (if you use it) if something fooks up