I have this function which works great to access the Web content of a specific HTML page:

    ' Get the HTML response from a server
    Public Shared Function GetUrl2(ByVal tcUrl As String, Optional ByVal tnTimeout As Integer = 5000) As String
        Dim lcHTML As String
        Dim lcUrl As New System.Uri(tcUrl)
        Dim loHTTP As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(lcUrl)
        loHTTP.Timeout = tnTimeout
        Try
            Dim loWebResponse As System.Net.WebResponse = loHTTP.GetResponse()
            Dim loStream As System.IO.Stream = loWebResponse.GetResponseStream()
            Dim loString As New System.IO.StreamReader(loStream)
            lcHTML = loString.ReadToEnd()
        Catch loError As Exception
            lcHTML = loError.Message
        End Try
        Return lcHTML
    End Function

But, I can't find the proper way to modify it so it will accept the username and password in order to authenticate against a page which requires a basic authentication.