adding a remote alarm to remote central locking

I have to install a remote alarm to a Holden Commodore 1994 model, ( you dont get them over there yet) (You will get the 2003 model rebadged as a Pontiac GTO.But other cars must be similar. I need to know how to link the original remote locking control to the new alarm remote, so there is only one controller.Either the original or the alarm control remote. Any information would be greatly appriciated. Thanx

Use the alarm control module's remote control because you will get better range ). All you need to do is to piggyback the OEM wiring and then you can use the aftermarket system as well as the oEM one as a back up if need be.