"re-code?"
I don't think they CAN be re-coded.
They can be unlocked using the correct code, but without the original VIN, that won't be happening. ONCE they are unlocked, they can be coded for additional features (CD changer, ipod interface, satellite radio, change the band center frequencies, set the acoustic properties for A3/A4/TT etc) using a VAG-COM, but they can't be re-coded so far as I know.
Keith