Not trying to burst your bubble (I want the return of Surfchu too) but it sounds like it is simply a code that prolly
A) turns active Pokemon to Pika/Raichu
B) Makes its first move Surf
If it does change the Pokemon, Colesium will revert it back anyways.
How does a site have GS codes for an unreleased game? It wont even hit Japan til Feb '04?