Subject Headers

I'm wondering if it's possible to get procmail or sendmail to edit the
subject line of an email when it resends it out to a ML, so that it
would add an [ML Name] <subject>?
I just installed it a couple days ago on an account and am still trying to
figure out all the nifty cool stuff (tm) that can be done with it.

Any help on this matter would be greatly appreciated.

Regards,
Sally Po