using From: instead of Return-Path: to reply to mail

hello,

I was wondering how I could somehow ignore the Return-Path in a message
and instead use the From: field to get a return address for an
autoresponder.  The message I wish to auto-respond to comes to my mail
server in the form

X-POP3-Rcpt: ddp(_at_)no1
Return-Path: web
Date: Fri, 25 Jul 1997 22:54:11 -0400
To: webmaster(_at_)ddpweb(_dot_)com
Subject: information
From: ddp(_at_)netmegs(_dot_)com

note that the Return-Path is always web, since I am using my server on a
form to send the e-mail...  basically I want to ignore this and use the
From: field.  Otherwise my auto-responder sends mail to the webmaster. 
WHOOPS!!!

Thanks for any help!!

Richard