[ChrisMillward]

At the moment there doesn't seem to be any means of simply Creating a virtual library or adding more books to an existing virtual library from a Selected (Highlighted) list of books. It can be done to a Library but NOT a virtual library. I would expect to be able to randomly select any group(s) of desired books, right click and see an option to 'Create a virtual Library' or 'Add to a virtual Library' Conversely there is no means of pruning a virtual library. I can remove books but this will delete them from the main library also. Sometimes the books aren't amenable to the search methods available which seem to largely work on a column basis. Yes, I could create a column "In" and mark it accordingly then delete and create virtual libraries as necessary.