Dunno whether you're in the US, but here in the UK, if you've found a code that you need on your remote (personally mines a Topline 8 / URC-8550), you telephone OFA's support line, explain what and explain what you need.

Then they tell you to press the key sequence that tells the remote you want to use the modem (I could describe this for mine, but it may be irrelevant to yours), hold it to the phone whilst they send the codes. On my remote, when it's finished, the word "COMPLETE" is displayed in the LCD window, momentarily.

You can then use the new code(s) to assign to device keys.

I don't understand your question about unsupported devices.

Cheers

Neil