Column Labels Are Numbers Instead Of Letters in Microsoft Excel 2013 Windows
Excel can be displayed column labels as numbers instead of letters.
This feature is called “R1C1 Reference Style”
Below information explains how to disable “R1C1 Reference Style” in Microsoft Office 2013.
First click the File tab.
Second, go to Options and click it.
From Excel Options tab, go to Formulas and click it.
Now columns label are letters.