Soluzione cancerogena alla lepre (fattela piacere)

Imports System.Text
Imports System.Text.RegularExpressions

Public Class Main

    Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub btn_apri_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_apri.Click
        Try
            dialog_apri.ShowDialog()
            txt_programma.Text = My.Computer.FileSystem.ReadAllText(dialog_apri.FileName, Encoding.Default)
        Catch

        End Try
    End Sub

    Private Sub btn_correggi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_correggi.Click
        Dim programma As String
        programma = txt_programma.Text
        Dim resultstring As String
        Dim rgx As New Regex("(?mn)^N\d+ ")
        Dim replacement As String = ""
        resultstring = rgx.Replace(programma, replacement)
        txt_programma.Text = resultstring
    End Sub

    Private Sub btn_salva_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_salva.Click
        Try
            dialog_salva.ShowDialog()
            My.Computer.FileSystem.WriteAllText(dialog_salva.FileName, txt_programma.Text, False)
            MessageBox.Show("File salvato in: " + vbCrLf + dialog_salva.FileName, "Salvataggio", MessageBoxButtons.OK, MessageBoxIcon.Information)
        Catch
            MessageBox.Show("Qualcosa è andato storto", "Errore", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub
End Class