38.1. Every local municipality which, as a result of an annexation, is situated in part in two regional county municipalities, shall form part as a whole, from the annexation, of the regional county municipality in which it was situated before the annexation. However, any adjudication, for unpaid taxes, of immovables situated in the annexed territory as well as any proceeding for the redemption of such immovables shall be carried out by the secretary-treasurer of the regional county municipality which effected the sale.