if you could just tell me the code for Germany I would be more than happy!
It isn't GE, DE, 49
Ok, I found it myself, in a roundabout way.
Apparently, the codes used are FIPS country codes. For anyone wanting to go Caching in another country, here's is a list of the codes used. It would be an obvious thing for Trimble to map them to international standards, but until then, at least you can enter them.
http://en.wikipedia.org/wiki/List_of_FIPS_country_codes