Decoding of and matching to RFC2047-encoded subjects?

Greetings,

What tools would you recommend for matching to RFC2047-encoded
subjects in procmail recipes?  Ability to handle 8bit character
sets like ISO-8859-1 is enough (I'll pass the decoded subject to
egrep; if it ends up being gibberish, I don't care, the regexp just
doesn't match it which is ok by design of my recipes).

-- 
Hannu