16 Pa.C.S. § 13301

The county commissioners shall appoint a county solicitor. The county solicitor shall be an attorney at law admitted to practice in the courts of this Commonwealth and may be an individual, a law firm, a partnership, an association or a professional corporation. Before entering upon the duties of office, the county solicitor shall file with the county commissioners an agreement to pay all fees, attorney fees and commissions received from every source as county solicitor into the county treasury.