Notwithstanding any provision of §§ 2.2-2814, 2.2-2815, 2.2-2816, 2.2-2823, 2.2-2824, 2.2-2825 or § 2.2-2826 to the contrary, whenever there shall be authorized by law an assistant attorney for the Commonwealth and such assistant’s duties consist of the prosecution of public assistance fraud cases pursuant to §§ 18.2-95, 18.2-96, 63.2-502, 63.2-513, 63.2-522, 63.2-523 or § 63.2-524, the Department may, with the consent of the attorney for the Commonwealth of the jurisdiction, contract with the county or city or combination thereof for whom such assistant attorney for the Commonwealth is authorized regarding the duties of such assistant and regarding the payment by the Department of the entire salary, expenses, including secretarial services, and allowances of such assistant, as shall be approved by the Compensation Board, for the entire time devoted to these duties. Any such contract may provide that the county, city, or combination thereof shall pay the entire amount of such salary, expenses, and allowances and that the Department shall reimburse such county or city therefor. The amount of such salary, expenses, and allowances shall be set by the Compensation Board as provided by law.