There is no "Make Your Own Character" station in LEGO Batman: The Videogame (Wii, 2008). The feature simply does not exist in this title.
No code, cheat, or glitch unlocks a creator in LEGO Batman Wii. It wasn't built. Play Free Play with the 50+ unlockable characters (Batman, Robin, Joker, Harley, Killer Moth, Man-Bat, etc.).