Counting names and email addresses in Excel

[theMAD2]

I thought I'd put this in here because it more likely to be a macro issue in Excel.

I've got a spreadsheet with lots of names and email addresses in grids. These are spread across several workbooks, each being a different department. What I want to be able to do is, if a name or email address occurs in the worksheets more than a set amout of times for this to be either flagged up or highlighted. Does anyone know if this is possible?

Any help appreciated

Thanks