On a PC, the file name is ENCase.txt, and in EndnotX9, it is located in
C:\Users(username)\AppData\Roaming\Endnote
(and AppData is a hidden folder on Windows), so you must view and search hidden folders)
I found it by searching the harddrive for that filename. I also first added something to it, and it was date stamped today.
The contents were in a plain text file, so you should also be able to search for text files with some of the words in your list, in case for some reason they named the file differently on a Mac?