Purchase Invoices and Reference field

At ‘Purchase Invoices’, when you create a new or edit an existing Purchase Invoice, you have the opportunity to enter information at the ‘Reference’ field. I use this to enter the filename of the scan of the invoice, so I can find the original invoice (the print-out I got at a shop or business).
Is there a way, or could you provide this, to make this a clickable link to the scanned item (it will also include the path to the file on my PC), so I can quickly check the info I put in the Purchase Invoice against the actual invoice?

@Roeland, Maybe you can add your suggestion to one of these topics.
It seems your asking a different way to attach invoices but your thoughts might help.