Well, this is isn't exactly what you need, but the IR carrier wave operates in a broadband range. Allmost all remotes use a 32khz signal (I think there's also a 41khz signal used by some manufacturors) that is either on or off. Kinda of like morse code over 1800s telegraph wires, with the IR carrier being the wires, the 32khz signal being the 1khz tone and the on/off pattern being the information. The pattern of off's and on's (presence/absence of the the 32khz tone) determines the key that was pressed. It's very easy to grab an IR reciever off the shelf and wire it up to the serial port. That way you can use the remote, but have your own custom downlink to the pc. This kind of stuff is very well documented in hardware hacker circles.