Attached is the source for a simple TCP proxy server. I whipped it up pretty quickly so it probably needs some refactoring if you plan to use it in production. The server class is loosely based on the Cassini implementation. You can set the listen port and forward host/port in the app config:

<configuration>

    <appSettings>

        <add key="listenPort" value="443"/>

        <add key="forwardHost" value="wush.net"/>

        <add key="forwardPort" value="443"/>

    </appSettings>

</configuration>