SOAP to FILE asynchronous with system acknowledgement

Hi,

My scenario is SOAP to FILE asynchronous scenario.

The sender system is a DOT NET based application which will trigger a service exposed by PI. PI will write a file at an agreed location.

Requirement is, the sender system wants an acknowledgement/confirmation that the file has been written successfully at the target side so that they can maintain a log table at their end.

How to achieve this?

Thanks in advance.