Private Sub CommandButton1_Click()
Dim derlig As Integer, i As Integer, lettre As String, augmentation As Range
Application.ScreenUpdating = False
Range("D2:D65536").ClearContents
derlig = Range("J4").End(xlDown).Row 'ligne de la dernière date
For i = 2 To Range("C65536").End(xlUp).Row
lettre = Application.VLookup(Cells(i, "E"), Range("G:H"), 2, 0)
Set augmentation = Cells(derlig, Application.Match(lettre, Rows(4), 0))
If augmentation.Text Like "*%" Then 'si l'augmentation est un pourcentage
Cells(i, "D") = Cells(i, "C") * (1 + augmentation)
Else
Cells(i, "D") = Cells(i, "C") + augmentation
End If
Next
End Sub