WM for Partners x TN x AS2

We have a following situation:
We are a B2B hub.
One of ours clients has a webMethods for partner and it needs send a EDI document to another client who has a EDIINT AS2 connection.
The issue is: the first client don´t want we see the document content. It just wants we forward the encrypted document to the another client by AS2 using our IS 4.6.

Client 1 (wM for Partners) -> HUB -> Client 2 (AS2 EDIINT)

How could I configure it in TN? Could I create a AS2 document in the webMethods for Partner? Any ideas?
Thank you,