HTTP in .NET Application

I have a VB.NET Windows application.
I would like to send an HTTP request to a web site and get back a response.

Something like:
------------------------------- MY WINDOWS APP CODE --------------------------------
DIM Req as httprequest
DIM Resp as httpresponse

httprequest.url = "URL to get"
httprequest.QueryString.add("Request", "Interfaces")
httprequest.exec
------------------------------- MY WINDOWS APP CODE WAITS FOR RESPONSE --

------------------------------ MY ASPX CODE ------------------------------------------
How do I send the results back.
response.write("Some XML String")  <<<< This would be HTML would it not?
response.QueryString.Add("Response", "XML List of Interfaces") <<<< I want to do something like this.
------------------------------ END MY ASPX CODE ------------------------------------------

------------------------------ MY WINDOWS APP CODE CONTINUES -------------------
Resp = httprequest.Response

Dim FullResponse as string = Resp.Response
Dim QString1 as string = Resp.QueryString("Response")  <<< Something like this

' Now I can process the return XML in the QString1 variable

----------------------------- ALL DONE ----------------------------------------------------

Need this fairly quickly.

Thanks