Once you've created a route in TOPO 7 you need to convert it to a Delorme .gpl file. It creates a track like log of your route. (you can also create a gpx file in Delorme but it only registers waypoints and vias and will not give you a smooth route like a course.)
Next, use the 'GPSBable' tool to convert the .gpl file to a .gpx file.
Then use 'TCX Converter' to convert your GPX file to a COURSE file.
Now either import it into Training Center andsync it with your Edge or copy it to your COURSE folder on the Edge.
It might seem a little cumbersome but it is actually quite easy and effective.
Many routes I tried to create in mapsource and save as GPX files would get truncated when I tried to copy it to the Edge. There is a serious limitation as to the length of route saved as a GPX file that you can use. It is actually quite rediculous that the software is so inferior to Delormes and lacking in the ability to create courses, especially when it costs 2 to 3 times as much.. I'm hot on this one - so I won't go there right now.