Whenever it shall be in the best interests of the county, the county executive is authorized and empowered to designate an agent or agents to assist the director of finance acting in his capacity of registrar for the principal or interest of any issue of bonds, notes or obligations of the county, whether issued or to be issued, for which the director has been or may be named as registrar by any resolution or resolutions of the county council authorizing the issuance or sale of such bonds, notes or obligations. The terms and conditions of the appointment of such agent or agents shall be fixed by the county executive; provided, that such agent or agents shall in all cases be a national bank or shall be a bank and trust company regularly engaged in business in the state, and such national bank or bank and trust company shall have capital and surplus amounting to at least three million dollars ($3,000,000.00). (1986 L.M.C., ch. 37, § 2.)