That’s right, and the best way to do it.
The way I mentioned above is the “old fashioned” way since version 8 or something when Endnote first had “URL” field. “Attachment” field was added later, but I’m still sticking with the URL field.
The advantage of URL field is (just to defend my “old fashioned-ness”), is that I can make URL links to hundreds of the PDF files in one (streamlined) action.
When I download bunch of Pubmed entries, I also download Pubmed ID numbers into Endnote library. Then, download PDF files to my local HD, with pubmed ID number as file name. Then, I copy the pubmed ID number to the URL field by Change&Move field command in Endnote.
Using the same “Change&Move field” command, I add “.pdf” after the pubmed ID numbers in URL field (without space). Then, I insert URL link text (as I detailed above) before the pubmed ID numbers without text.
This way allows me to make the absolute URL links to the PDF files in a semi-automated way. When I use “Attachment” field, I have to do it one by one. Do I? Also, “Attachment” field doesn’t allow me to use ctrl+G (open link) command, which became my figer habit after years.
Bottom line: You can do both (URL link or Attachment with “absolute” link option).
Best regards,