Thank you so much for the reply. I am pasting a couple of screenshots (one from one of the Devonthink file that needs a link and the other from Endnote reference management system that has files with attached PDF). The idea would be to be able to open up the reference file in Endnote at a click from a link in Devonthink file so that I can open and read the PDF using KM.
Let me know if you need any other screen shots or information. I really appreciate your expertise!