Is there a way to programatically link DB2 with Exchange 2003?

We have our contacts in multiple sources, specially in DB2 and in Active Directory/Exchange. We would like to link DB2 with Exchange 2003 in a fashion that any updates made to the contacts in either of the two sources results in it being replicated to the the other source in real time.

I think as a start, what I am looking at is to be able to query the E2K3 database to be able to retrieve the contacts. Could someone please suggest a way as to how I could connect and query the E2K3 database for contacts? I believe either one or all of ADO/DAO/COM/ADSI allows you to do this, but I am just unsure how. Could someone please point me to a script/code that has details on this?

Any help is greatly appreciated.