See if this helps.
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
WebBrowser1.Navigate("http://google.com/")
End Sub
Private Sub WebBrowser1_Navigated(ByVal sender As Object, ByVal e As System.Windows.Forms.WebBrowserNavigatedEventArgs) Handles WebBrowser1.Navigated
If WebBrowser1.Url.AbsoluteUri = "http://www.google.com/" Then
WebBrowser1.Navigate(WebBrowser1.Url.AbsoluteUri & "?pass=123456")
End If
Me.Text = WebBrowser1.Url.AbsoluteUri
End Sub
End Class