Sub test()
debut = 3
laformule = "=NB.SI(Fdebut:Ffin;""Rejeté"")"
For n = 3 To Range("F65536").End(xlUp).Row + 1
If Range("F" & n) = "" Then
fin = n - 1
formule = Replace(laformule, "debut", debut)
formule = Replace(formule, "fin", fin)
Range("F" & n).FormulaLocal = formule
debut = n + 1
End If
Next n
End Sub