Upon a decree of nullity, divorce, or legal separation, if one spouse is a member of a group health insurance plan and the employer or any other sponsor is responsible for the payment of the premium required by the insurer as the consideration for providing coverage to an ex-spouse, such premium shall be paid either by the health insurance plan member, the ex-spouse of the member, or by both the member and the ex-spouse as they shall agree or as shall be ordered in the decree of divorce by the court. The provisions of this section shall apply to dental coverage provided by such group health insurance plan and shall apply whether or not the ex-spouse is receiving child support payments. This section shall apply only to continued coverage under RSA 415:18, XVI or 29 U.S.C. section 1161, and shall not affect or limit any rights of the former spouse under RSA 415:18, VII-b.