(a) An order for child support shall provide that payments of such support continue beyond the date when the child reaches the age of eighteen, so long as the child is unmarried and residing with a parent, guardian or custodian and is enrolled as a full-time student in a secondary educational or vocational program and making substantial progress towards a diploma: Provided, That such payments may not extend past the date that the child reaches the age of twenty.
(b) Nothing herein shall be construed to abrogate or modify existing case law regarding the eligibility of handicapped or disabled children to receive child support beyond the age of eighteen.
(c) The reenactment of this section during the 1994 regular session of the Legislature shall not, by operation of law, have any effect upon or vacate any order or portion thereof entered under the prior enactment of this section which awarded educational and related expenses for an adult child accepted or enrolled and making satisfactory progress in an educational program at a certified or accredited college. Any such order or portion thereof shall continue in full force and effect until the court, upon motion of a party, modifies or vacates the order upon a finding that:
(1) The facts and circumstances which supported the entry of the original order have changed, in which case the order may be modified;
(2) The facts and circumstances which supported the entry of the original order no longer exist because the child has not been accepted or is not enrolled in and making satisfactory progress in an educational program at a certified or accredited college or the parent ordered to pay such educational and related expenses is no longer able to make such payments, in which case the order shall be vacated;
(3) The child, at the time the order was entered, was under the age of sixteen years, in which case the order shall be vacated;
(4) The amount ordered to be paid was determined by an application of child support guidelines in accordance with the provisions of section one hundred one, article thirteen, et seq., of this chapter, or legislative rules promulgated thereunder, in which case the order may be modified or vacated; or
(5) The order was entered after March 14, 1994, in which case the order shall be vacated.