Try this, but it will depend on how your player's software operates. First, I assume that the field being set to 'Various Artists' is the ALBUMARTIST field (Or possibly 'ALBUM ARTIST' with a space). If so, you may be able to use ALBUMARTISTSORT to dictate the sort order. You can either use the Extended Tags dialog to set this field, or create a column or Tag Panel field for it. Use something like 'zzzVarious Artists', as you suggested.
If your player recognizes ALBUMARTISTSORT, then it will still appear as 'Various Artists', but will sort to the bottom of the list. I prefer it to be at the top of the list, so I use '! Various Artists' instead.
To edit this field I recommend creating a Tag Panel field, as the Tag Panel is best for editing any album-wide fields. Do Ctrl-O (Options) > Tag Panel > Add field... (button), and set 'Field:' to 'ALBUMARTISTSORT' and set 'Name:' to whatever you like, such as 'Album Artist Sort'.
If your player does NOT recognize and use ALBUMARTISTSORT, then the only solution may be to change the ALBUMARTIST field itself. Using 'zzzVarious Artists' may not be the most visually appealing, but it will work. Instead, you can probably use some innocuous character as a prefix to force sorting to the bottom. Try '~Various Artists'.