No, im not comparing changes between two of the same files (which is
what your addin seems to do) I am looking at two sepearte spreadsheets
and referencing cells between them. In fact if it is able to be done
( I hightly doubt it) a feature that would be awesome is to have the
same exact workbook open on each monitor. And then be on different
sheets in the workbook so that you can reference a cell from a
previous sheet without having to switch tabs.

Make sense?