So I just had one of my teams ask me this question and the only thing I had for them is to put the row number in the Title of the attachment when they attach a file to a row in a sheet. That way, when they need to export a sheet for an audit, they can download all the attachments and send them with the sheet and the auditor will know that attachment A goes with row 12 because row 12 is part of the title of the attachment.
My question, is there a better way to do this so that the attachment retains some sort of identifier that it belongs to a specific row, or the sheet when it is exported, lists the titles of the attachments and what row they belong to?