Rob I wrote:
I have two worksheets in excel 2003 and I want to check if there are any
matches from column C on worksheet to with worksheet ons column F. They are
numbers and leters that I need to match up if any and then highlight. What is
the best formula to use or way to complete this?

For matching, check into VLOOKUP. Perfect for matching one column
against another.

For highlighting, perhaps conditional formatting will do the trick.