You can use replication preprocessor http://wemcode.wemblog.com/replication-preprocessor or replication listner. If you are creating new replication from code then simply use replicator.replicate(Pass your modified path that exist in repository)
Regarding pre processor if we implement and deploy this service. It may apply to all the replication agents in the instance right? Do you have any idea for restricting this to specific agent?
the preprocess method has a ReplicationAction object in its parameters. Use the http://dev.day.com/docs/en/cq/current/javadoc/com/day/cq/replication/ReplicationAction.htm l#getConfig() method to get the AgentConfig and filter accordingly.
but rewriting the path, where the payload of a replication should be stored, would be a new feature to me :-) Because then you would need to rewrite the "CQ-Path" and the "CQ-Handle" headers sent along with the replication request. And these are out of reach of the public API.