Romantsch (various names and spellings) is spoken by a small minority of Swiss (all of whom are also competent in German and most also in other languages) in a couple valleys (particularly the Engadin) in the far SE part of the land. It is a form of the language called Rhaeto-Romanic, which also has speakers (a much larger number, though with less official support) in NE Italy (and possibly also some in Austria or Slovenia, not sure about that).

I can probably come up with a reasonable Esperanto version for you.

Liland