[NTG-context] automatically "smashing" È in xml typesetting

Hello list, I'm typesetting italian text that contains "E" letters with a grave accent, like this: "È". In my "body font environment" the interline space is narrow and those "È" make their lines taller, making every following line move downwards. The problem is easily solvable putting "\smash" before "È". But my sources are XML and typesetting is done through xmlsetups, so I'm looking for an automatic way to replace every "È" in the text with "\smash{È}". Is it possible? Thanks, Massi