add data to toccontrol

When i open MXD file, it isn't add to TOCControl, but it is dispalyed. How solve it or it is imposible? Code from standart ArcEngine MapControll APP

private void menuOpenDoc_Click(object sender, EventArgs e)
    {
        //execute Open Document command
        ICommand command = new ControlsOpenDocCommandClass();
        command.OnCreate(m_mapControl.Object);
        command.OnClick();
    }

Or this(adding to TOCControl) i can do only for layers?