EDI - Include Customer DUNS# in Outbound PO to Vendor

Hello,

We are using ECC 3.0 and creating IDOCs which are mapped to EDI documents via a translator. 

Current Inbound Configuration

For our inbound POs from our customers, we maintain the relationship between the Customer and the Ship To in EDPAR.

Need Help with Outbound EDI Configuration

We'd like to do something similar with our outbound POs for certain vendors.  If the outbound PO is a drop ship order (i.e., shipping from the vendor to a customer), we'd like the ability to include the customer's DUNs number in the IDOC.

Is this something we can maintain in EDPAR?  If not here, then where?

Thank You,

Karen