Parsing out POST Form data in before transmit POST

Dear FiddlerCore people:

I would like to capture the Http POST stream to the server to extract the FORM and Cookie data.

I would like to only have a proxy for the current proc. This code sets the proxy for all the browsers, and

breaks the internet on proxy using browsers while I'm working on this. I'm only interested in one particular

windows forms browser http call. I can capture the cookies from the forms browser  but not the FORM in the

header. So I have to capture the call data with Fiddler. Once I have the data from the client prepared for the server,

I want to CANCEL the call and abort the forms browser call and do a HTTPWebRequest using the cookies and FORMS data.

A session is the http web request and response?

I'm only interested in the request and I will edit the request and send a HTTP web request with the environment

of the forms browser.

My problem is that the website code spawns a new browser outside the thread I control in the form web browser.

I want to intercept the call and either edit it so it does not spawn a new client thread, or send the request in http webRequest and webResponse.

I'm looking at the oS data structure and starting to see what it contains. 

 What is the best way to edit this and cancel the current request in the session?

          Fiddler.URLMonInterop . SetProxyInProcess ( "127.0.0.1:8888" , "<-loopback>" );
            Fiddler . FiddlerApplication . Startup ( 8888 , false , false );
            //Fiddler . FiddlerApplication . Startup ( 0 , FiddlerCoreStartupFlags . Default );

             Fiddler . FiddlerApplication . BeforeRequest += delegate ( Fiddler . Session oS )
                {
                Debug . WriteLine ( "Before request for:\t" + oS . fullUrl );
                Debug . WriteLine ( String . Format ( "{0}:{1} >>{2}<<" , oS . id , oS . PathAndQuery, oS.RequestHeaders, oS.RequestMethod ,oS.RequestBody.ToString() ) );
                string code;
                List<Fiddler.Session> oAllSessions = new List<Fiddler . Session> ( );
                oS . bBufferResponse = true;
                Monitor . Enter ( oAllSessions );
                oAllSessions . Add ( oS );
                Monitor . Exit ( oAllSessions );
                };