Hi,

You can try the following snippet:

...
this.XGrid.MouseRightButtonUp += new System.Windows.Input.MouseButtonEventHandler(XGrid_MouseRightButtonUp);
this.XGrid.MouseRightButtonDown +=new System.Windows.Input.MouseButtonEventHandler(XGrid_MouseRightButtonDown);
...
private void XGrid_MouseRightButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
    System.Windows.Point p = e.GetPosition(Application.Current.RootVisual);

    IEnumerable<HeaderCellControl> elements =
        VisualTreeHelper.FindElementsInHostCoordinates(p, Application.Current.RootVisual).OfType<HeaderCellControl>();

    HeaderCellControl headerCellControl = elements.FirstOrDefault();

    if (headerCellControl != null)
    {
        headerCellControl.Cell.Column.HeaderText = "Right clicked!";
        e.Handled = true;
    }
}

private void XGrid_MouseRightButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
    e.Handled = true;
}
...

HTH