I've got an unknown-but-highly-archaic version of Squirrel running in two locations, and was in a similar situation. My vendor basically said that while it's techincally possible to get the printer codes, it wasn't easy, and would involve trying to track down a friendly party at both Squirrel and possibly the printer vendor. As time was of the essence, I opted to get a Squirrel-compatible printer. If that's an option for you, it may be the path of least resistance in this case.