''He looks nothing like me. He's gone to seed,'' Napoleon Bonaparte (Ian Holm) says of the grubby commoner smuggled over to St. Helena to masquerade as the exiled ruler while the real Napoleon, disguised as an Everyman, escapes back to France in the clever historical comedy The Emperor's New Clothes. That the grubby commoner is also played by Holm is a big part of the fun of this pleasingly puzzle-shaped diversion, based on the novel ''The Death of Napoleon'' by Simon Leys. HBO-seasoned Alan Taylor directs with a great appreciation for romantically photographed weather as a mood signifier, and apparently an equally great appreciation for ''The Madness of King George'' as a role model.
While Holm, as Napoleon, visibly softens and loosens over time as he adapts slowly to everyday life (tenderized by the affection of ''High Fidelity'''s Iben Hjejle as a good, widowed Everywoman), Holm, as the inelegant impostor, visibly puffs and hardens as grandeur goes to this nobody's head. And he does it all with the smallest, most intimate of adjustments to his gait, expression, and voice. It's a royal, finely modulated double performance by an actor who always wears his powers with graceful modesty.