18.—(1) The Lord Chancellor may by regulations make provision—
(a)as to the sums that may be directed or ordered to be paid under regulations 13, 16 or 17, whether by specifying rates or scales or by making other provision as to the calculation of the sums;
(b)as to the circumstances in which and conditions under which such sums may be paid or directed or ordered to be paid;
(c)requiring such sums to be fixed having regard to regulations under paragraphs (a) and (b);
(d)requiring such sums to be calculated in accordance with such regulations (whether or not that results in the fixing of an amount that the Appeal Court considers reasonably sufficient to compensate the person concerned);
(e)as to the review of determinations of sums directed to be paid under regulation 13.
(2) Regulations under this regulation may provide that provision as to the calculation of sums (whether in the form of rates or scales or other provision) may be determined by the Lord Chancellor with the consent of the Treasury.