=SOMMEPROD(('2008'!$P$2:$P$38000=$B$1)*('2008'!$L$2:$L$38000=$C$3)*('2008'!$O$2:$O$38000=""))
'Pour recuperer le resultat
Sub Test()
MsgBox Application.Evaluate("SUMPRODUCT(('2008'!$P$2:$P$38000=$B$1)*('2008'!$L$2:$L$38000=$C$3)*('2008'!$O$2:$O$38000=""""))")
End Sub
'Pour poser la formule dans la cellule
Sub Test1()
ActiveCell.FormulaR1C1 = "=SUMPRODUCT(('2008'!R2C16:R38000C16=R1C2)*('2008'!R2C12:R38000C12=R3C3)*('2008'!R2C15:R38000C15=""""))"
End Sub