Honestly it's not that big a deal. But you should be able to use a DTMF sender and decoder. I'm just not that familiar with the letter of the law, and what is considered 'remote control' or encrypted communication, as what the signal is used for is very important in FCC law. I think FRS/CB/GFRS is pretty well locked down to voice only, but then again all the 'security codes' are is a data sensitive squelch, it sends an identification tone out when you hit the button, if the code doesn't match the one it's set for it squelches the audio. But that's built into the device itself, and hooking up an external audio source changes things, so it's a little weird.