I have a similar situation where my '97Cam came with the factory alarm but no remotes
I got one off ebay that should work, but the car won't respond while using the instructions to program it.
I talked to a shop about bypassing and adding an aftermarket system, but it usually ties into the factory system somehow for it all to work. We looked in the manual to see if it had a dedicated fuse, but there are two fuses to the factory alarm. One with the horn, and one with a whole bunch of thing like dome lites, etc. So it doesn't seem reasonable to do that either.
I've asked about a reset switch or method but no one seems to know.
a2z, try turning your key twice to unlock all four doors when unlocking the drivers door. That may disarm the alarm for you while just getting in.
Anyone else has have suggestions?