This obviously doesn't work but it's what I'm going for...I don't even know where to start.  Could someone give me a little pseudo code to start with?

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim _serviceXML As New XmlDocument
        Dim xServices As XmlNodeList
        Dim xpath As String

        _serviceXML.Load("c:\servicesToTree")
        xpath = String.Format("/AccountInfo/Location[@LocationID={0}]/Product[@ProductLineID = '100002']/Configuration/Service", 550061)
        xServices = _serviceXML.SelectNodes(xpath)

        UltraWebTree1.DataSource = xServices
        UltraWebTree1.DataBind()
    End Sub