I've kinda done this. A year ago I got a One 4 All universal remote that didn't understand my stereo. Their tech support emailed to me a WAV file, and told me

I've kinda done this. A year ago I got a One 4 All universal remote that didn't understand my stereo. Their tech support emailed to me a WAV file, and told me to hold the device up to my computer speakers when I played it. Bingo, reprogrammed remote. I remember back ~1986, living in a fraternity house in college. My direct-connect modem died, and I borrowed an acoustic one from a friend. The guy in the room next to me had his stereo cranked up, which seemed to interfere with the modem. I wrapped the acoustic coupler up in a couple of layers of towels, and everything was fine.