Private Sub Button2_Click(sender As Object, e As EventArgs) Handles _
  Button2.Click
        Dim txt0 As String = "150521"
        Dim txt1 As String = TextBox3.Text.Substring(0, 2)
        Dim txt2 As String = TextBox3.Text.Substring(2, 2)
        Dim txt3 As String = TextBox3.Text.Substring(4, 2)
        Dim txt4 As String = txt3 & "." & txt2 & "." & txt1
        Debug.Print(txt4)
    End Sub