[Dovecot] Exempt mailboxes from indexing?

I looked through the wiki and the archives, but couldn't find an answer to this question.

We use a webmail product that uses three dummy mbox dotfiles for storing configuration and temporary info. I'm trying to find a way to have dovecot's indexing ignore all dotfiles, and so far have had no luck (other than, of course, coding it in myself).

Does anyone know if this is possible? Thanks.

-Brian Hayden