Section 29B. The first justice for the Nantucket county court may, with the approval of the chief justice of the probate and family court, appoint a clerk who may administer the oaths required in probate proceedings that are not prescribed by law to be administered by the judge or register, and shall perform such clerical and other duties as may be required by the first justice, with the approval of the chief justice. The clerk may be removed by the first justice with the approval of the chief justice. The register may, with the approval of the chief justice, designate 1 employee as deputy assistant register and with the approval of the chief justice remove a deputy assistant register. The deputy assistant register shall receive additional compensation in an amount equal to 15 per cent of the annual salary of the Nantucket county register of probate.