DiffEngineX

DiffEngineX is a utility that finds the differences between the formulae, constants, defined names and cell comments contained in either two whole Excel workbooks or selected worksheets. DiffEngineX is for Windows operating systems only (Windows 2000/XP/2003/Vista/Windows 7). It works with any version of Microsoft Office/Excel from 2000 to 2007.
It generates a cell-by-cell difference report in a new workbook and color highlights different cells in automatically made copies of your workbooks.
As Excel spreadsheets get modified over time new rows and columns can be inserted between existing ones. DiffEngineX can align both similar rows and columns in the sheets being compared.
It has many powerful features such as the ability to hide matching rows, group like changes to adjacent cells and highlight differences at the character level. It can be used from its user interface or programmatically using command-line arguments.
DiffEngineX can also compare databases (prior sorting step required) and comma separated value (CSV) files once they have been imported into Excel.