In order to teach your RF 20 some other codes that are available online in hex format, you would have to get the URC CCP software, and a URC computer programmable remote. You could then simply take the hex codes available online and paste them into the CCP software. This could be a hex code from anywhere online, not just a specific database. The only requirement (obviously) would be that the code actually does something on the device you are trying to control.

Once you have pasted the hex code into the software, you'd assign that code to a button on the computer programmable remote that you have. You'd download the code, and then use that remote to teach your RF 20 the code.

So from the sounds of it, you're missing two vital pieces of the puzzle at the moment: the URC CCP software, and a URC computer programmable remote.

Another alternative is if you buy a cheap Logitech Harmony remote online, I have heard that if you call up Logitech support and provide them with a hex code, they can add it into your remote's profile so that you could then use that remote to teach your RF 20 the codes.