How do I make SPIP call different .html files for different rubriques ?

I have a rubrique.html which applies layout to all rubriques : through rubrique.php3 SPIP calls lauout in rubrique.html. All works fine, but now I want SPIP to use a different layout (different .html file) to, for example, rubrique with id=6. Is it possible ? How do I do this ?
I’m grateful for all answers or hints...