Código:
Dim FileDialog As New OpenFileDialog
Dim FileReader As System.IO.StreamReader
FileDialog.Filter = "dll|*.dll|Visual Basic Script|*vbs|Todos los documentos|*.*"
FileDialog.CheckFileExists = True
FileDialog.Title = "Abrir"
FileDialog.ShowDialog(Me)
Try
FileDialog.OpenFile()
FileReader = System.IO.File.OpenText(FileDialog.FileName)
FileReader.ReadToEnd()
Catch ex As Exception
End Try