I think Liga's original question may have been simpler than that. You can just use:
Create Ulm god Version 1.
Start new game using Ulm.
Create Ulm god Version 2.
Start another game using Ulm.
and they won't interfere with each other. You would need to back up the files if you wanted to keep your Ulm Version 1 to use when creating future games.
Thanks to all ... so, as far as the game is now, I can start different game with different pretemder of the same nation, but if I want to resuse on of them I need to make a manual backup.