A party or support enforcement agency seeking to modify, or to modify and enforce, a foreign child support order not under the Convention may register that order in this state under sections 14-5-601 through 14-5-608 if the order has not been registered. A petition for modification may be filed at the same time as a request for registration, or at another time. The petition must specify the grounds for modification.
Procedure to register child support order of foreign country for modification
Colo. Rev. Stat. § 14-5-616, under Registration, Enforcement, and Modification of Support Order.
Colo. Rev. Stat. § 14-5-616