Applicatin Engine - Shudown

We are using a delivered process that loads purchase card info. We want to schedule it to run daily. However if the AE program runs and the file is not available the engine abends. We want to alter the delivered engine PO_CCPCRDSTG check for the files existance and if not there shutdown, not abend. Without rewriting the flow of the whole engine this does not seem to be possible. Is there not a peoplecode command to shutdown further processing of the current instance of the engine returning a success?

Somthing like :

If not FileExists (filenamestring, filepathtype) then ?Shutdown? end-if;