to take the place of someone temporarily
I’ll be sitting in for the secretary at/on the meeting tonight.
Is the use of "sit in for" common or is this one used more:
He's taking place of her for a day.
Which one is used more "sit in for" or "take somebody's place"(temporary)? And can "on" be used instead of "at" for the meeting? I'll be sitting in for the secretary on the meeting.