How do you highlight a range of cells, then enter a formula into only one without losing the others?

I'm trying to set a matrix formula in a cell, and the answer will be a column vector. To get a column vector as the answer, first I have to highlight the number of cells that will be in the vector, otherwise the answer will only be generated in the cell with the formula. How do I highlight several cells in a... show more I'm trying to set a matrix formula in a cell, and the answer will be a column vector. To get a column vector as the answer, first I have to highlight the number of cells that will be in the vector, otherwise the answer will only be generated in the cell with the formula.

How do I highlight several cells in a column, then enter a formula into the first one without the others being automatically un-selected?
Update: In Excel on a Mac, to be clear.
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