How to search .* files?

DZ <[email protected]> Tue, 1 Sep 2009 20:49:00 +0000 (UTC)

Newsgroups	gmane.comp.gnome.dashboard.devel
Organization	S<13N<3 !1!
Message-ID	<[email protected]>

Is there a way to tell beagle to search certain plain text dot files,
like .bash_history and .Rhistory?

I tried to make an external filter but didn't succeed.