Sterling VAN connectivity from SAP PO

Dear folks,

We have a scenario where trading partners are placing their 850 and other ANSI X12 EDI messages in the Sterling VAN.

From there SAP PO has to pick up the EDI messages and should be converted into IDOCs and other way round also.

Which B2B addon adapter is having the capability to connect to Sterling VAN to pull the EDI messages or Push the EDI messages?

Thanks

Sridhar Goli