Asynchronous Transactions With Xml Https Post

I basically have a few thousand transactions 7,000 - 10,000 transactions to process over a short time. The flow goes like this.

---> ----> ---> ---> receive (1000) as each transaction takes approx 2 seconds so if i were to process synchronously it would take all night......

Now first i would like to ask if i am going about this the right way ? the service i am communicating with is not .net but is built to handle large amounts of requests. I have obtained the following code that suggests it will do what i am after

dim strxmlreq as string = '(this is where i input my xml string)
Dim request As HttpWebRequest

' Create the request

[CODE]...

The problem i have is if the above will work for me where exactly do i catch the returned xml string ? I assumed "result" would be the xml output string.