series.Points.Add(New NumericDataPoint(5.0, labelId, False))

chart.Series.Add(series)

         Dim handler As New Infragistics.UltraChart.Shared.Events.ChartDrawItemEventHandler(AddressOf DrawItem)
            AddHandler Chart.ChartDrawItem, handler

...

 Private Sub DrawItem(ByVal sender As Object, ByVal args As Infragistics.UltraChart.Shared.Events.ChartDrawItemEventArgs)
            Dim _text As Text = TryCast(args.Primitive, Text)
            If Not _text Is Nothing AndAlso Not String.IsNullOrEmpty(_text.Path) AndAlso _text.Path.EndsWith("Legend") AndAlso Not _text.Column = -1 Then
                Dim labelIdAs Long = CLng(_text.Value)
                If _labelDictionary.ContainsKey(labelId) Then
                    _text.Value = _labelDictionary(labelId).Name
                End If
            End If
        End Sub

            Dim labelRenderers As New Hashtable
            labelRenderers.Add("CUSTOM", New LabelRenderer(_labelDictionary))
            Chart.LabelHash = labelRenderers
            Chart.Legend.FormatString = "<CUSTOM>"

....

     Public Class LabelRenderer
        Implements Infragistics.UltraChart.Resources.IRenderLabel

        Private _labelDictionary As IDictionary(Of Long, NamedObject)

        Public Sub New(ByVal labels As IDictionary(Of Long, NamedObject))
            _labelDictionary = labels
        End Sub

        Public Function ToString1(ByVal context As System.Collections.Hashtable) As String Implements    Infragistics.UltraChart.Resources.IRenderLabel.ToString
            Dim label As String = Convert.ToString(context("ITEM_LABEL"))
            If Not String.IsNullOrEmpty(label) Then
                Dim labelId As Long = CLng(label)
                If _labelDictionary.ContainsKey(labelId) Then
                    label = _labelDictionary(labelId).Name
                End If
            End If
            Return label
        End Function
    End Class