<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="connectionString"
         value="Provider=Microsoft.Jet.OLEDB.4.0;
Data Source=
F:\Transmitter.mdb" />
  </appSettings>
</configuration>

Imports System.Data.OleDb
Imports System.Configuration
Module DBVerbindung
    Sub Main()
        Dim connString As String = ConfigurationSettings.AppSettings( _
          "connectionString")
        Dim conn As OleDbConnection = New OleDbConnection(connString)
        conn.Open()
        ' mit der Verbindung etwas machen ...
        conn.Close()
    End Sub
End Module

Dim connString As String = _
  System.Configuration.ConfigurationManager.ConnectionStrings( _
  "connectionString").ToString

Pdt