We achieved such requirement by using idoc type STATUS. Create a new receiver for this idoc interface. New receiver should be the sender ECC system and message type is STATUS idoc. you can update idoc number and status changes based on message mapping.
Ideally status 18 can be send for all IDOC received to PI from ECC.
If it is errored out, create an alert mail and tie it up with one interface to generate status idoc of status 05 and 11
