Sub Bouton50_QuandClic()
Dim i As Byte
Dim j As Byte
For i = 5 To 96
For j = 48 To Cells(65536, i).End(xlUp).Row
Select Case Cells(j, i)
Case 2: Cells(j, i) = 'B'
Case 3: Cells(j, i) = 'C'
'etc....
End Select
Next j
Next i
End Sub