Attachments of POs & Invoices from R/3 to SRM

In a PO, we can create attachemnts using GOS (Icon on the top left hand corner).

So, when I transfer PO data from R?3 to SRM using XI, all these attachments are also to be sent.

How can I do this?

DO I need XI or any standard procedure is there to handle this or any ABAP coding is required for this?

Please share your thoughts on this.

The same way, data should flow between SRM EBP to SUS along with the attachments.

Thanks

Kiran