Using factory and custom remotes?

I JUST bought a 1996 Buick PA today, and it has a cutom keyless remote, called "Passive Hijack Version IMPULSE 3100" it has an audible "chirp-chirp" when it's armed and disarmed (ie, unlocked). I was wondering if I can also use GM's standard keyless remotes with this car? I have a couple left over from my 1993 Park Avenue Ultra and would like them to be of use.

Also, is the connector for programming the remotes under the dash, drivers side, like it was on the 1993 Park Avenue Ultra?

You can't use the GM remotes with your current alarm system.

93 and 96 remotes are different. So is programming.