VS 2008 Read And Extract Xml From Webbrowser?

I'm using the following code to read the xml from the url and it works nice,but how can i convert the code to read the xml from webbrowser instead of the direct url

here is the original code if i use direct link "http://xxxxx": i want to put instead webbrowser1.??

Dim doc As New XmlDocument()
doc.Load("http://xxxxxx")
Dim navigator As XPathNavigator = doc.CreateNavigator
Dim title As XPathNodeIterator = navigator.Select("/channel/item/title")