Numbers: Can I highlight the row and column of the selected cell?

Solution 1:

If I understand your question, Numbers does this by default - note the darkened row and column identifiers in the image below at AK50.

Edit: ah, I see.. okay, I found an inconvenient hack:

• Select the Column containing your target cell
• Cmd click the cell above (or the Cmd Click the row index of the cell above)
• Cmd click the Row containing your target cell
• Cmd click to reselect the cell above your target

Like so:

Maybe you could use automator to make this less painful?

Solution 2:

Another method, useful for selecting a range of rows in a column, is to click on the uppermost cell you want to select, scroll down to the bottom of the range, shift-click on that cell. All rows between will be selected (in addition to the two you clicked on).