Keyless Entry.
 

I have a 1998 Honda Civic with a aftermarket radio installed.

So this is my problem I have my remote that came with the car and it still works since I had the stereo installed at Crutchfield. So my remote is slowly dying and I have another remote from a 09 accord. Is there anyway I can program this to the car. And if not how to program another remote like I have since there is no factory radio to press the button?

I do not believe that it would work without the original radio. They must have pushed it into the back area. I'd look for it there. Then you can press the radio button when you get a replacement.