To add custom button on title bar of docking pane

C = MDIDockingPaneManager.CreatePane(5, 200, 120, DockingDirection.DockLeftOf, B)
C.Title = "Pane 5 - Menu Button"
C.Options = XtremeDockingPane.PaneOptions.PaneHasMenuButton

Private Sub MDIDockingPaneManager_PanePopupMenu(ByVal sender As Object, ByVal e As AxXtremeDockingPane._DDockingPaneEvents_PanePopupMenuEvent) Handles MDIDockingPaneManager.PanePopupMenu
    If e.pane.Id = 5 OrElse e.pane.Id = 2 Then
        paneContextMenu.MenuItems.Clear()
        Dim newItem As System.Windows.Forms.MenuItem
        Dim x As Integer
        For x = 0 To 14
            newItem = New System.Windows.Forms.MenuItem(MyColor(x).ToString())
            AddHandler newItem.Click, AddressOf mnuPanePopupItem_Click
            paneContextMenu.MenuItems.Add(x, newItem)
            If arrPanes(MDIDockingPaneManager.ActivePane.Id - 1).rtfTextBox.BackColor.Equals(MyColor(x)) Then
                newItem.Checked = True
            End If
        Next x
        paneContextMenu.Show(Me, New Point(e.x - Me.Left - 4, e.y - Me.Top - MDIDockingPaneManager.Top + 6))
    End If
End Sub