What do you get when you run process.bat all by itself? That's the one that's actually calling cgpsmapper, but without a PATH, your MP file and cgpsmapper will both need to be in the same folder. cgpsmapper should show up in a CMD line blue window. Although since TransCode.bat calls cgpsmapper.bat you may just see the Transcode window. Depending how big the map is the windows should stay open for a while.
My unofficial batch file follows. You'll need to edit the path to suit your installation
path=c:\program files\cgpsmapper;%path%
for %%i in (*.mp) do cgpsmapper ac %%i
pause
This will compile all MP files in a folder, and will keep the command window open after the compile has run, until you hit the return key.