[AccessD] How to insert a tag into an invoice?

Hi all,


I have the following situation to deal with at one of my customers.

They scan the invoices they receive, and store the file into the file
system.

When the invoice get paid, they want to insert a tag (kind of validation
signature) into the electronic file of the invoice,
before saving it into a different directory.

How would you the tag insertion? Is it  at least possible?

Thanks in advance for your input.

Philippe