Inbound EDI 850 (POI) to create sales order attachment

We have a custom process where a order details come in via spreadsheet and is used to load the sales order header and lines interface tables and create sales orders. Once the order is created, we call APIs to create certain header and line level attachments. The attachment text is also exists in the spreadsheet.

We are in the process of making this order import an EDI 850 - POI, the customer would be sending EDI files instead of spreadsheet going forward. When we do this, can the Inbound EDI 850 process be used to import header/line level attachment after the sales order is imported. If this is not possible, is there a good way to create the attachment. Any other ideas are appreciated.