----------------------------------
        Dim ColumnName3 As String = "F5"
        Dim templateColumn3 As New MyCustomFilteringColumn(xL5)
        templateColumn3.DataField = "BSF5"
        templateColumn3.HeaderText = "F5"
        templateColumn3.UniqueName = "A5"
        templateColumn3.AllowFiltering = False
        Me.RadGrid1.MasterTableView.Columns.Add(templateColumn3)
------------------------------------

  Public Class MyCustomFilteringColumn
        Inherits GridBoundColumn

        Private dsx As DataTable
        Private item As XPathNodeIterator

        Public Sub New(items As XPathNodeIterator)
            item = items
        End Sub

        Protected Overrides Sub SetupFilterControls(cell As TableCell)
            Dim rcBox As New RadComboBox()
            rcBox.ID = ("DropDownList1" + Me.UniqueName)
            rcBox.Width = Unit.Pixel(130)
            rcBox.AutoPostBack = True
            rcBox.DataTextField = Me.UniqueName
            rcBox.DataValueField = Me.UniqueName
            rcBox.DropDownAutoWidth = RadComboBoxDropDownAutoWidth.Enabled
            AddHandler rcBox.SelectedIndexChanged, AddressOf rcBox_SelectedIndexChanged

            For Each it As XPathNavigator In item
                Dim tmp As String = it.Value.ToString()
                Dim pp As New RadComboBoxItem
                pp.Text = tmp
                pp.Value = tmp
                rcBox.Items.Add(pp)
            Next
            rcBox.Items.Insert(0, New RadComboBoxItem("----"))
            cell.Controls.AddAt(0, rcBox)

        End Sub

        Protected Overrides Sub SetCurrentFilterValueToControl(cell As TableCell)
            If Not (Me.CurrentFilterValue = "") Then
                Dim CC As RadComboBox = DirectCast(cell.Controls(0), RadComboBox)
                Dim PP As RadComboBoxItem = CC.Items.FindItemByText(Me.CurrentFilterValue.Replace(""", Chr(34)))
                If PP IsNot Nothing Then PP.Selected = True
            End If
        End Sub

        Protected Overrides Function GetCurrentFilterValueFromControl(cell As TableCell) As String
            Dim currentValue As String = DirectCast(cell.Controls(0), RadComboBox).SelectedItem.Value
            Me.CurrentFilterFunction = If((currentValue <> "" Or currentValue <> "----"), GridKnownFunction.EqualTo, GridKnownFunction.NoFilter)
            Return currentValue.Replace(Chr(34), "&quot;") '.Replace(Chr(39), Chr(39) & Chr(39))
        End Function


        Private Sub rcBox_SelectedIndexChanged(sender As Object, e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs)
            ' DirectCast(DirectCast(sender, RadComboBox).Parent.Parent, GridFilteringItem).FireCommandEvent("Filter", New Pair())
            Dim filterItem As GridFilteringItem = DirectCast(DirectCast(sender, RadComboBox).NamingContainer, GridFilteringItem)
            filterItem.FireCommandEvent("Filter", New Pair("EqualTo", Me.UniqueName))
        End Sub


        Protected Overloads Overrides Function GetFilterDataField() As String
            Return Me.DataField
        End Function

        Overloads Overrides Function SupportsFiltering() As Boolean
            Return True
        End Function


    End Class