We want to store files with purchases but we o not want to use Dropbox. We would like the ability to either..

Create a 'link' to a file resource either via http:// or file://

or

Have the notes field recognise valid URI's thereby giving us a way to reference an online resource and click on it. This would open in a new browser window displaying the target of the click. That might be a file we have stored in OneDrive, SharePoint or elsewhere or it might be a web page related to the purchase.