In all cases where a prospective purchaser advances the expense therefor the county auditor may employ a special attorney to act for the state in prosecuting to judgment an action to quiet title and a proceeding to register title of any tract of land which the prospective purchaser is interested in purchasing when the state shall have first procured a Torrens certificate of title therefor; or for the purpose of procuring a new certificate of title in favor of the state by the necessary proceeding for that purpose where the title to the land is already registered under the Torrens system.