COUNTIF on Multiple sheets

Hi,

I have a workbook with alot of sheets, each sheet is identical in format. What I am trying to achive is a way of counting all the occurances of a name in a range of cells on all sheets.

To try and explain, each sheet has a drop down list in cells C5:V5, and I need to try and get a way of a summary sheet showing how many times "J.Bloggs" appears in All Sheets accorss the range C5:V5, but am finding it impossible.

Any help grately appreciated

Thanks

Wil