Tracing messages in SAP PI 7.0

Hi,

Please let me know how to check the messages in PI 7.0 using message ID provided by other middleware system.

Flow is source system ---> non-sap middleware(messaging system)--->SAP PI --->SAP ECC.

Message ID provided by non sap middleware system is different from PI Message ID.In this case ,how to check the messages in PI 7.0.

Does payload based message search possible in PI 7.0.?If so,how does it achieved in PI 7.0?

Regards,

Karthiga