The chief judge of each district shall have the following administrative duties and authority with respect to his district:
If no judges are available under subdivision a, b or c, then a substitute judge shall be designated pursuant to § 16.1-69.21.
While acting, any judge so designated shall have all the authority and power of the judge of the court, and his order or judgment shall, to all intents and purposes, be the judgment of the court. A general district court judge designated pursuant to subdivision 1 a, may, with his consent, substitute for or replace a juvenile and domestic relations district court judge, and vice versa. The names of the judges designated under subdivisions b and c shall be selected from a list provided by the Executive Secretary and approved by the Chief Justice of the Supreme Court.
Va. Code § 16.1-69.35