In cases involving a neglected or abused child, when a guardian ad litem is appointed for the child as provided in N.H. Rev. Stat. § 169-C:10, the cost of such appointment shall be paid from funds appropriated for indigent defense pursuant to this chapter. In cases involving a neglected or abused child, when an expressed interest attorney is appointed for the child as provided in N.H. Rev. Stat. § 169-C:10, the cost of such appointment shall be paid from funds appropriated for indigent defense in this chapter. In cases involving a neglected or abused child, when an attorney is appointed to represent a parent determined to be indigent pursuant to N.H. Rev. Stat. § 169-C:10, II, at the preliminary hearing or a hearing pursuant to N.H. Rev. Stat. § 169-C:6-a, III, whichever occurs earlier, the cost of such appointment, including counsel and investigative, expert, or other services and expenses, shall be paid from funds appropriated for indigent defense pursuant to this chapter. Counsel shall petition the court for investigative, expert, or other services necessary to provide adequate representation. If the court finds that such services are necessary and that the parent is financially unable to obtain them, the court shall authorize counsel to obtain the necessary services on behalf of the parent. Services authorized under this section shall be in addition to payment for expenses provided under N.H. Rev. Stat. Chapter 169-C or RSA 170-C.