Sub Reformat1()
Dim xCell As Range, Plage As Range, x As String, z As String, y As Byte
Set Plage = Range("D1:D" & Cells(Rows.Count, "d").End(xlUp).Row)
Plage.NumberFormat = "@"
For Each xCell In Plage
If Len(xCell.Value) < 14 Then
x = xCell.Value
y = 14 - Len(xCell.Value)
z = Application.WorksheetFunction.Rept("0", y)
xCell.Value = z & x
End If
Next xCell
End Sub