In those districts having more than one district court judge, the presiding circuit court judge may designate from time to time a district court judge, who shall have the same powers and authority as a circuit judge to handle all cases involving domestic relations, divorce, annulments of marriage, custody and support of children, granting and enforcement of alimony, proceedings under the Reciprocal Nonsupport Act and all other domestic and marital matters over which the circuit court has jurisdiction as well as all laws pertaining to juvenile and nonsupport cases arising in the county under Title 30 of this code and who shall serve as an ex officio circuit judge when handling such cases, regardless of any provisions contained in this title or any other laws to the contrary; provided, that in those counties having one district judge and in which a circuit judge is currently empowered to handle the aforementioned classes of cases as well as juvenile cases, such power and authority shall not transfer to the district judge without the express authorization of the presiding circuit judge.