The MX-850 is very old, but still a capable remote.

You *do* need the software to program it, and the issue with the software is the remote needs a serial (RS232) port for communications, which is no longer current technology and isn't included on much. There are USB/Serial adapters, which can work, but not all do and some have difficulty with them.

If you can afford it, URC's newer remotes with USB will be less of a hassle, but you have to buy from a dealer who will bundle the software (it's not included nor required to be included).

Beyond URC, for a computer programmable remote you'll pretty much be stuck with a Harmony!