i think this solution should work.
you can use Gamespy Comrade software. download the software & install. login with your "old" accountnick (victory day) and password -> rename accountnick & change e-mail-adress -> start MoW -> create new gamespy account with your "old" name -> use your CD-key. now you can use your "old" accound nick.
http://comrade.gamespy.com/
or create new gamespy account with special characters in your name. eg. -=MyName=-, [xyz]MyName
other solution:
start windows regedit.exe and navigate to key [HKEY_CURRENT_USER\Software\1C\Men of War]. here can you change "test key" to "bought key".