The Office of Executive Secretary to the Supreme Court, to be filled by a person having the qualifications as may be prescribed by the justices of the Supreme Court, is hereby created to be the court administrator for the Commonwealth. He shall be appointed by the Supreme Court, shall hold office at the pleasure of the Court, and during his term of office shall not engage in the private practice of law. He shall receive such compensation as may be fixed by the Court. He may, with the approval of the Court, employ such persons as are necessary for the performance of the duties of his office, whose compensation shall be fixed by the Court within the limits of the amounts appropriated by law.