If there is a vacancy in the office of the clerk of court of common pleas, county auditor, or county treasurer at the time fixed for preparing the jury list or for drawing a jury or if any of these officers are disqualified or unable to serve for any reason, the county judge of probate shall act in his place and stead and if there is a vacancy in two of these offices or for any other reason two of these officers are unable to serve, the county judge of probate and the sheriff of the county shall act in their places and stead. If from among the officers above named there are not three persons in office qualified and able to serve, the resident circuit judge or the presiding judge shall appoint a commissioner or commissioners to serve in the place of the commissioner or commissioners as may be disqualified during the time of his or their disqualification. Each of the substitute commissioners shall receive the same per diem and mileage as is paid jurors.