Thanks, capnm, for your hint, it sounds good
I've been using "reading list" since some time syncing mainly "from search": you cannot define here a column to update.
After your answer i've additionally defined another list "populated from books on device": with this one i can define a column to update with "Y/N".
Unfortunately, after that i still do not see an entry "add to list" in the conext of the right click. Where is it hidden? Or what's wrong about my settings?