procedure goes like that:
Save your map from GPSMapEdit as *.mp file. Compile this file with cGPSmapper. Alternatively export img form GPSMapEdit.
Create *.pv control file file as described in cGPSmapper manual, chapter 9.
Run cpreview.exe with pv file as an option.
Compile preview map created by cpreview.
Install your map using MapSetToolKit, use button "Install".
See your map in BaseCamp.