Well I don't know how this would be coded, but I don't think you could do it for PAST users tha have never posted, but the idea I have would work for anyone in the future who doesn't post.
Idea:
- Post counts add normally in applicable forums, anything more than 1 means the user has posted and will not show up when searching for "non-posting" users.
- Post counts in forums that do not add to post counts will not be added to the postcount, BUT, they will be added to a new table that is created. This will not be seen publically in any way, but is simply for searching purposes.
- Then, any user who has both 0 postcount and 0 noncountingpostcount (long word lol) will be considdered a "has never posted" user.
It is a good idea. It wouldn't be terribly hard to do, but I don't really have time to look into it now. That's just my theory on how it could work.