Acknowledgement of Idoc of EDI type

Hi all,

We have the following scenario :

R/3 > Idoc (asynchronous) > PI BPM > Http (Synchrnous) > B2B Partner (EDI Customer (ALE KU))

We want to acknowledge our idocs using a node of the XML contained in HTTP response.

It seems we can't use ALEAUD to do that because our target isn't a logical system (EDI communication)

Is there a way ???

Thanks a lot.

J.C.