How to forward mail without changing Return-Path?

Hi 

When I forward my mail with procmail using ! , I found the Return-Path: is
inconsitence with From: . Th From: keep the same,but the Return-Path: has
been change to the address who do the forwarding . When I use mailx to
replay the mail , The address doing the forward and the old From: both
appear in the To: . I don't want to change anything when I forward mail .
How can I do it ?

Best Regards

Hong Ge