postfix help, please

[David]

We are currently running postfix as our edge relay server.   All email is currently forwarded to an internal Notes server.
We are also in the process of migrating to exchange.   I have no problems with getting the mail to exchange, however, the powers that be want all incoming mail to be delivered to both the new exchange server and the old Notes server.

Basically
 
                           -> joe.user at domain.com (exchange server)
in -> joe.user at domain.com -
                           -> joe.user at domain.com (Notes server)

I have 2 issues.   If I specify exchange.domain.com and notes.exchange.com will the "to" address be re-written?

Also, How the heck can I do this?  The closest I could find was:

http://www.lslnet.com/linux/edosc/52/linux-52354232.htm

but the translation isn't perfect, and I believe some of the characters aren't getting displayed correctly.   Mainly, this regex:

/^ (. +) $ 1 at backend1.x-si.orgx-si\.org$/ $ 1 at backend2.x-si.org

Any help would be appreciated.

David

-- 
"I find your lack of faith disturbing."
--Darth Vader