How to redirect messsage within sendmail

[jason_v]

I have a php script that changes the bounced e-mails to send to a specific address.

The pattern used for bounce addresses is b
[e-mail], where is a wildcard.

This means that I will need to have Sendmail send all
addresses matching that pattern to a script or a POP3 account.

any ideas of how I would do that?

thx