Chris, I am able to do what you want.
My bibliographic records were converted to End Note from Reference Manager and assigned a record number. Customer serice helped with this. New references are assigned a sequental record number. The Record Number can be seen in the Reference LIst Panel on my computer by adding the Record Number to the Display Fields. This is done by Edit-Preferences–see the Introduction to EndNote in the Help Menu.
Hope this helps,
Joe