The judges of each circuit court may appoint, in addition to commissioners of accounts, assistant commissioners of accounts who shall perform all the duties and exercise all of the powers required of the commissioner of accounts in all cases in which the commissioner of accounts is so situated that he cannot perform the duties of his office or in which the commissioner of accounts is of the opinion that it is improper for him to act. Assistant commissioners of accounts may perform such duties and exercise such powers in any case except cases in which he is so situated that he cannot act or in which he is of the opinion it is improper for him to act. Assistant commissioners of accounts shall act only in such cases that the commissioner of accounts delegates to him. An assistant commissioner of accounts making a settlement of a fiduciary account under the provisions of this section shall, within 30 days, report the fact and date of the settlement to the commissioner of accounts, who shall make an entry of the settlement in his record books. The person appointed as an assistant commissioner of accounts shall be a discreet and competent attorney-at-law and shall be removable at the pleasure of the court.