Dim reg As Microsoft.Win32.RegistryKey
Dim app As String
Dim path As String
Dim fileext As String = ".xls"
reg = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(fileext)
app = reg.GetValue("").ToString
If Not app = String.Empty Then
  reg = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(app + _
    "\shell\New\command") ' command Eintrag öffnen
  path = (reg.GetValue("").ToString) : path = path.Substring(0, path.IndexOf( _
  "/")) ' Paramter entfernen
  path = path.Remove(0, 1) : path = path.Remove(path.Length - 2, 1) ' 
  ' Hochkommas entfernen 
  If MessageBox.Show(path + " starten ?", "", MessageBoxButtons.YesNo, _
    MessageBoxIcon.Question) = DialogResult.Yes Then
    Process.Start(path) ' starten
  End If
End If