Mandrill Webhooks Interspire For Bounce Processing Integration

We have a set up of Interspire, PMTA and Mandrill. The problem is that Interspire can not process bounce emails since mandrill masks the bounce address with its own. So we are left at the mercy of mandrill webhooks. We need a way where bounced addresses from mandril are sent to a particular email address which later interspire can read to process them. Any body who has setted up a similar system would know exactly what we are talking about here and would probably come up with a concrete solution. I am looking for realistic applications, address our problem particularly and tell us the plan of action in the application. No need to hefty cover letters.