need procmail expression help

[Eric Wood]

I'd ask this on the procmail mail list but I can't seem to subscribe to it..
they may be down.

I have this rule:
* ^Subject:.*[ ][ ][ ][ ][ ][ ]+

which will test of there is a least 6 consecutive spaces in the subject
line.  However, I don't care if the subject line has trailing spaces.  How
can I trim off the trailing spaces so that I only care about leading spaces
and whatever spaces are in between the words?

-eric wood