Private Function RechComm(prenom As Range, comm As Range)
Dim lp&, fc&
Application.Volatile
lp = Application.Match(prenom, Columns(1), 0)
fc = Cells(Cells(lp, 3).End(4).Row, 3).End(4).Row
RechComm = Application.WorksheetFunction.countif(Range(Cells(lp, 3), Cells(fc, 3)), comm)
End Function