Export attachments using siebel EIM

Hi everybody, I ran an EIM job to export opportunity attachments which is a one time job that has to be run to export data to another application. The files are generated in the output folder while the attachment record is in the eim_opty_dtl table.

From here the files will be transported by a file transport interface that is in use here at the customers enterprise and the attachment record would be sent through the same interface.

However, i can see a problem here. When the receiving application gets the data they would not know which file belongs to which opportunity. The files in the output folder only have the filename. What if 2 opportunity records have the same filename. How would that be distinguished?