Sub ReplaceTravaux_4()
Dim c As Range, i&, j&, T As Variant
Application.ScreenUpdating = False
Set c = [D7:AD10000]
T = c
For i = LBound(T, 1) To UBound(T, 1)
For j = LBound(T, 2) To UBound(T, 2)
If T(i, j) = "A" Or T(i, j) = "D" Then T(i, j) = "S9"
Next j
Next i
c = T
End Sub