How do I grab particular google results with vb.net? to listbox

I know howto make the vb program go to Google, even navigate around but I don't know how to manipulate the results.
Basically what I want the program to grab search results from Google and retrieve links specified by the user for instance if the user searches for Burgers and they only want results from Burgerking.com. Then only those would be output to the listbox. Does anyone know how to do this? here's my code so far:
Public Class Form1

Dim look, retrieve As String

Private Sub Search_Click(sender As Object, e As EventArgs) Handles Search.Click
look = InputBox("What are you looking for?")
look = look.Replace(" ", "+")
Dim G1 As String = "(google.co.uk)=en&tbo=d&output=search&sclient=psy-ab&q="
WebBrowser1.Navigate(G1 + look)

retrieve = InputBox("What links do you want to retrieve?")

End Sub

End Class

I know it is easier to use the google api. But it is also a lot slower, i've used it in the past. I've just seen in another thread howto download a website's source and pretty quickly just don't know how to grab the urls from the downloaded source. Is anyone here any good with string manipulation?

Code so far:
sourcecode = ((New Net.WebClient).DownloadString(G1 + look))