Rated 1 star because it's just a matter of opening the Game.exe file witha hex editor and replacing an entry.

Open the Game.exe file with a hex editor, search for (ASCII String) "%s's_game" and replace it with anything you like; non-alphabetical/numerical characters aren't allowed with the exception of _ and ' and the length can't be longer than what it originally was or it'll cause errors when players with a long nickname try to host a game. "%s" will be replaced by the nickname of the player that hosts a game with the modified game.exe file.