I'm sorry to get sticky on the wording, but just to get it right, when we say “in that capacity”, it works in the original wording, but it doesn't work when you're saying “chair or vice-chairs”. You're going to have to say “act as chair at or during a meeting”.
I'm sorry, but we have to be accurate. If you say “in that capacity” once you've said “chairs or vice-chairs”, “in that capacity” refers to something different from what it did in the first instance.