You should just be able to reprogram the remote fob from the '02 to work on the '99. A lot easier to do than pulling some module out. Takes all of 30 seconds to reprogram the remote to the car. Flip the ignition switch a few times, press the buttons on the remote, and done. Could probably do a search on the site for a how-to, or even Google it. If nothing else, just find a remote fob for your '99 on eBay or Amazon and do the reprogram. You can get the remotes for dirt cheap...I bought a spare for my Explorer for like $10, and programming it was a breeze.
EDIT: I think I understand better what you're saying after rereading that. I'm fairly sure that all the vehicles came with a remote fob by that year. Unless you've been the only owner of that '99 from day 1 and know for a fact that it never had a fob, then all you'd need to do is reprogram a remote. But if it has always lacked the ability to do the remote feature, I can't say for 100% certainty that you'd only need that module.