xquantite = TextBox24.Value 'Valeur de la textbox quantité = valeur variable
If xquantite <> 0 Then
xquantite = xquantite - 1
Range("B8").Select
Selection.End(xlDown).Select
Selection.Offset(1, 0).Select
ActiveCell.FormulaR1C1 = "=R[-1]C+1"
ElseIf xquantite = 0 Then
Exit Sub
End If
Loop