Notwithstanding anything in section 6 of this Act, a person holding the office of sheriff principal or sheriff may, without relinquishing that office, be appointed by the Secretary of State to assist him to discharge the functions vested in him in relation to the organisation and administration of the sheriff courts, but a person so appointed shall not perform his duties as the holder of the office of sheriff principal or sheriff, as the case may be, while he retains that appointment.