Va. Code § 17.1-110
When all the parties to any cause pending in a circuit court, or their attorneys of record, shall enter into a written stipulation appointing a judge pro tempore for the trial of the cause and approved by a judge of said court in his discretion, and the person appointed shall take and subscribe an oath faithfully to try and determine the issues joined between the parties, the clerk of the court in which such action or suit is pending shall record the stipulation and oath. The person appointed shall be vested with the same power and authority and shall be charged with the same duties as to the cause in and as to which he is appointed as though he were the regularly elected and qualified judge of such court. However, the parties may, by the terms of their stipulation, limit the power of the judge pro tempore to the trial and determination of any specified issue or issues, either of law or fact and in such cases the oath of the person appointed shall correspond to the terms of the stipulation.
The provisions of this section and § 17.1-109 shall be in addition to the provisions of § 17.1-105.
Va. Code § 17.1-110