Perhaps I assume incorrectly...
CPaps are used in a bedroom. receptacles are common. Are DC cigarette lighter receptacles now common in RV bedrooms?
The poster claims limited knowledge. You want HIM to somehow tap into a concealed DC bedroom 12 volt source.
"SIMPLICITY INCORPORATED" stated a "simple cord purchase" would get the poster a power cord to reach all the way from an existing cigarette lighter receptacle all the way back to the bedroom.
I can only sadly shake my head.
Reminds me. I have to go into the drawer and scrap a half dozen JUNK GRADE cigarette lighter plugs. You know, it really doesn't matter if the positive breathing apparatus fails at 2AM in some remote campsite.