Open the site you want to search, right click and select "View Source" or "View Source Code". This will bring up a html page with the source code. Search through the code for the textbox name, will normally be txtSearch or something similar.
After the search, make your browser visible, all the searched criteria will be there. You can add this to the listbox by manipulating the source code again. After search, view the source code and capture the names to be displayed. Add these to your listbox.
Dim myElement as HtmlElement
myElement = Webbrowser1.document.GetElementById("The name of the element here")
Dim Value as String = myElement.GetAttribute("value")
MessageBox.Show("Here is the value: " & Value)