Retrieving data sent from a vb app to an asp page

[Edward]

I'm using a vb application to post xml to an asp page. I'm using MSXML2.XMLHTTP30
in my vb application. My question is how do I retrieve the xml data that
I sent from my vb application in the asp page so that I can use dom to use
the data?

Here's a snipet of the vb code:
Dim xmlHttp As New MSXML2.XMLHTTP30

xmlHttp.Open "POST", txtUrl.Text, False
xmlHttp.setRequestHeader "Content-type", "text/xml"
xmlHttp.send strPostBody 'Xml data

I'm able to do this from one asp page to another because I can use the request
object and get the form element I set in the sending asp page(i.e. Request.Form(txtXml))
However, I'm not sure what the format is when I send it from a vb or a c++
application.