There is a current thread on this topic in the OFA remotes section with people that have Panasonic HDTV's.

[Link: remotecentral.com]

Keep in mind there are only 256 EFC's =Advanced codes.
If an EFC is above 255 just keep subracting 256 until it is below 256. I notice over there they arre refering to EFC 692 and that is the same as 692-(2*256)=180

-Jon