(1) If a testator purports to make an appointment by his or her will in exercise of a power of appointment, the appointment is not valid unless the will is—
(a) executed in accordance with this part; or
(b) under part 2A, to be taken to have been properly made.
(2) If power is given to a person to make an appointment by a will that is executed in some particular manner or with some particular solemnity, the person may exercise the power by a will that is executed in accordance with this part but is not executed in that manner or with that solemnity.