OK, this is what I've found so far:http://www.hifi-remote.com/forums/viewtopic.php?t=3026
Discusses the "chipped remote" vis-a-vis a Panasonic DMR-E55 DVD recorder.
It seems that there is either a "Service" remote or at one time was a "Development" remote, that was used to set up these models of Panasonic DVD. Some of the links at Videohelp.com suggest that these remotes are still used at Panasonic service centers. The "hacks" comments for other Panasonic players also seem to agree that this only works for European (region 2) players.
I traded some PM's with the Robman -- one of the "grandest daddies" of them all with respect to remote control hacking. He's the owner of Hifi-Remote.com, and has been active there, on the other remote forums, and even over here. He's a member of the team which "decoded" the JP1 interface on UEI "One-for-All"/Radioshack remotes.
What he said is that holding the "shift" button down causes "setup" to send a different signal. There are a limited number of "free" IR commands. (I believe that it is 256 codes / 8 bits). These are listed for the codeset which controls the DMR-E55 on the thread I linked to above. It is likely that this is the same device which controls the other panny DVD player (if it isn't determine which it is, and I will see if I can get the unused codes list from Rob).
With a UEI "One-for-All"/Radioshack remote, you can manually send each of these "unused codes" and see if the macro worked.
The idea is that you would:
1) Send the unused code. On the UEI remote this is done by pressing "setup" then the 3 digit code
2) Send "enter enter" (this can be a macro)
if the menu pops up, you are good to go.
He points out, that if you have a JP1 cable (the interface between the remotes and the PC, you could "upgrade" a device that has the whole code string, and then only have to press one button instead of 5 or six.
Unfortunately, while I have a JP1 remote/cable, I don't have one of these players. The UEI remotes can be purchased for under $20 from almost any electronics store. You can also purchase them in Europe (http://www.oneforall-int.com/index.html
If anyone manages to determine the "missing remote code" -- let me know, we will want to "publish" the information in the various remote control forums.