copy central locking codes between keys?

I've been searching all over the web for hours trying to find out how to do this without success. I've got a 1999 Mitsubishi Legnum VR4 (JDM) with a factory key with remote central locking, and just received a new key from Japan. The problem is I have no idea how to copy the central locking codes from one key to another (or indeed just sync the key to the car) and Mitsubishi here don't want to help as the car's a grey-market import. Does anyone have any idea how I might go about this? There are no ID codes on the key for ignition authorisation or anything, just remote central locking. Thanks! Trevor

I'm afraid you might  have to approach a dealer and bluff them, you will probably find that keyless entry is not available on that year except for Japan, Europe and possibly Australia use transponders, your other bet is a grey importer, yes I'm jealous because I've got a 1999 Galant 2000!