What transport protocol (HTTP/s, JMS, TCP, etc.) is BizManager using to communicate to XYZ application?
It sounds like the virtualization is outside of SAP, so I would start with:
Set up a DevTest recorder between BizManager and XYZ and ensure that you save a Raw Traffic file during recording.
Point BizManager to the DevTest endpoint.
Point DevTest to the XYZ endpoint.
Submit transactions.
When processing the recording, apply the EDI X12 Data Protocol Handler.