[NCLUG] Sendmail configuration "+" notation?

[Benson Chow]

I hope this doesn't turn into yet another sendmail versus ... iis? or
whatnot war, but what I want to do is to make sendmail accept

blc-submailbox at q.dyndns.org

work like the usual "+" notation ala "blc+submailbox at q.dyndns.org" as most
people are familiar with.  I am clueless at sendmail.cf decyphering but I
have a feeling these recipies in my stock config file:

R<@> $+ + $* < @ $* . >
                        $: < $(virtuser $1 + * @ $3 $@ $1 $: @ $) > $1 + $2 < @ $3 . >
R<@> $+ + $* < @ $* . >
                        $: < $(virtuser $1 @ $3 $@ $1 $: @ $) > $1 + $2 < @ $3 . >
R<@> $+ < @ $+ . >      $: < $(virtuser @ $2 $@ $1 $: @ $) > $1 < @ $2 . >

have something to do with it.  What will I need to add for both + and - to
work?  My guess is to replace some of the " + " with " - " but i'm just
making random guesses :)

Oh, the reasoning behind this "hack" is to satisfy the stupid websites
that don't like people putting +'s in their usernames but take hyphens
fine.   Fine, I'll put a hyphen in and make my mailer do the same thing.
Grr.

Thanks,

-bc