Saved from a previous post...
If the changes do not include removing rows or columns (or inserting rows or
columns), then you could use a program written by Myrna Larson and Bill
Manville.
You can find a copy on Chip Pearson's site:
http://www.cpearson.com/excel/whatsnew.htm
look for compare.xla
But remember this does a cell-by-cell comparison against two worksheets--not
workbooks. A1 compares to A1, x99 to x99, etc. (So if you insert/delete a
row/column, the comparison goes south very quickly.)
Another option could be to save the worksheets (not workbooks) as a couple .CSV
files. Then use some text comparison file to find the difference. (MSWord has
this ability.)
But this compares text (current values of formulas). Not the formulas
themselves.