marking folders if there's at least one new mail

[Johannes Zellner]

Hi,

is it possible to mark folders (with a flag or color)
if there's at least one new (or unread) mail inside ?
-- I let procmail direct mails of large-bandwidth-mailinglists
to separate folders. Now I'd like to change to a folder
by
    c=<tab>
which opens the default folder directory and I'd like to
see quickly in which folders I've new mail.

-- 
   Johannes