I would like to know if I right-clicked on the cell header.  How do I do this?

My current code:

    Private Sub ugCommission_MouseUp(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles ugCommission.MouseUp
 
        Dim cmItemNum As New ContextMenuStrip
        Dim cmCommDue As New ContextMenuStrip
 
        If e.Button = Windows.Forms.MouseButtons.Right Then
 
            Dim ptCurrent As Point = New Point(e.X, e.Y)
            Dim uiElement As Infragistics.Win.UIElement = CType(sender, UltraGrid).DisplayLayout.UIElement.ElementFromPoint(ptCurrent)
            Dim ugCell As UltraGridCell = uiElement.GetContext(GetType(UltraGridCell))
            Dim ugRow As UltraGridRow = uiElement.GetContext(GetType(UltraGridRow))
            ' Thought ugUIElement would be it, but it is also nothing when I right click on the col header cell
            Dim ugUIElement As UltraGridUIElement = uiElement.GetContext(GetType(UltraGridUIElement))
 
            If ugCell IsNot Nothing Then
 
                ugCommission.Selected.Rows.Clear()
 
                ugRow.Selected = True
 
                If ugCell.Column.Key = "ITEM_NUM" Then
 
                    _cmItemNum.Show(ugCommission, ptCurrent)
 
                ElseIf ugCell.Column.Key = "COMM_DUE" Then
 
                    _cmCommDue.Show(ugCommission, ptCurrent)
 
                End If
 
            End If
 
        End If
 
    End Sub