Neb. Rev. Stat. § 76-232

Any person interested in a deed that is not acknowledged, may, at any time before or during the proceedings before such officer, file, in the office of the register of deeds of the county where the lands lie, a copy of the deed, compared with the original by the register of deeds, which shall, for the space of thirty days thereafter, have the same effect as the recording of the deed, if such deed shall within that time be duly proved and recorded.