soap-proxy interface

Hi Experts.

I have an scenrio, i need to design the two interaces, first one is synchronus interface , it get the request from user (wsdl) and post the data in sap (using proxy) , once the data is arrived in sap, an ackownledgement ( error/ status) sent back to user,

the second asynchronus interface is to send the response ( to the request sent from first interface) back to the client system

( proxy--> soap used)

my query is how can the the second interface is triggered in runtime, if i write the code in report (proxy), do i need to schedule the background job ?

please explain indetails

Thanks

NV