N.H. Rev. Stat. § 311:13
From the commencement of an action, bill in equity or other proceeding in any court, the filing of a counterclaim or plea in set-off or recoupment, or appearance in any proceeding before any state or federal department, board, or commission, the attorney who appears for a client in such proceeding shall have a lien for reasonable fees and expenses upon the client's cause of action, upon the judgment decree or other order in the client's favor entered or made in such proceeding, and upon the proceeds derived therefrom. The lien cannot be affected by any settlement between the parties before or after the judgment decree or other order. Upon the request of the client or the attorney, the court in which the proceeding is pending, or, if the proceeding is not pending in a court, the superior court, may determine and enforce the lien; provided that this section shall not apply to matters arising under RSA 282-A and any case where the method of determination of attorneys' fees is otherwise expressly provided by statute.
RSA 311:13
1963, 89:1. 1996, 117:7, eff. May 15, 1996.