File Attachments in Endnote X7

Is it possible, using AppleScript, to attach a file to an Endnote X7 entry?

I have several (i.e., 2000-ish) .pdfs stored in a local directory that I would like to attach to their corresponding Endnote X7 entries using relative links. I can set the file attachment field to an absolute link pointing to the original folder. But I can’t seem to attach a file using a relative link so that Endnote can manage my .pdfs.