Follow these steps to change column from numeric to alphabet
Clear the R1C1 reference style selection in Excel preferences.
Difference between A1 and R1C1 reference styles
On the Excel menu, click Preferences.
Under Authoring, click General
Clear the Use R1C1 reference style check box.
The column headings now show A, B, and C, instead of 1, 2, 3, and so on.
I hope this is helpful!