To specify which notation format you want to use, follow these steps if you
are using a version of Excel prior to Excel 2007:

1. Choose Options from the Tools menu. Excel displays the Options dialog
box.
2. Make sure the General tab is selected.
3. If you want to use R1C1 format, select the R1C1 Reference Style check
box; if you want to use A1 format (the default for Excel), clear the check
box.
4. Click on OK.

If you are using Excel 2007, follow these steps instead:

1. Click the Office button and then click on Excel Options. Excel
displays the Excel Options dialog box.
2. At the left side of the dialog box, click Formulas.
3. If you want to use R1C1 format, select the R1C1 Reference Style check
box; if you want to use A1 format (the default for Excel), clear the check
box.
4. Click on OK.

"Bill C." wrote:

How do I get my columns to be letters again? I came to work this morning and
they were numbers and it's causing me issues when trying to create formulas.