To do Alt + N C 2 on Mac in Excel, download and install Accelerator Keys, then press Option, followed by N, C, and 2.
Command: New Comment
This is how to do Alt + N C 2 on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + N C 2 inserts a new comment on the selected cell. Comments allow you to add notes, feedback, or explanations to cells. In newer Excel versions, comments support threaded conversations for collaborative review.