I came across your thread while looking to see if anyone knew the right code for the URC 8810 to use with the Panasonic ES10. I have learned a tip which may help you out.
Contrary to published info, any button on the controller can be a "learning" button, not just L1-L4. In your instructions (
[Link: ofausa.com]) there are instructions for "programming a learning key." Instead of using the device key (dvd, tv, etc.) and L1-L4, use device key (dvd) and whatever key you want (play, rec, etc.). Easy as pie. Probably the best thing to do (which I am about to do, if there's no perfect code) is to find the code that works the best, then just learn the few commands that don't work. I had a dvd player, though, where I had to teach it every code, and that took a few minutes... But, it can be done...
Hope this helps.