think of a way of doing this easily...
You may want to think about formulas combining the EXACT and/or MATCH functions. There may be a way of doing this.
I suspect, ( but don't know how!), that this could be done using VBA. If one of the other regular Excel/VBA champs doesn't come up with something you may find help at click here
ANd just to save any confusion... you say "2 seperate worksheets"... You do mean workSHEETS don't you? I.E. they are in the same workBOOK. The solution would be different in this case.