Update Metadata and DOcument from Biztalk To Sharepoint(MOSS)

My Requirement is as follows:
1.Our partners plan to send meta-data in xml format and associated document(PDF) separately.  
2. We’ll do some further processing on the meta-data received from our partners and send it Sharepoint along with the associated document.

Is there is a good/suggested approach to send data and documents from Biztalk to MOSS? Challenge is how to send meta-data that is within biztalk and documents that is in some folder to MOSS as one single transaction.

Please suggest.