How to change the default number format in Excel?

Question

I have this column of string integers in the \'general\' type all the time. Every time I open this spreadsheet, I have to convert it into \'number\' type. But when I do it,

Answer 1

wrote a tiny macro

    Sub PERS_FormatSelectionToNumberNoDecimals()
        Selection.NumberFormat = "0"
    End Sub

... in my PERSONAL.XLSB.

In my data workbook's ThisWorkbook module (VBA editor) I place a function

    Private Sub Workbook_Activate()
    ' Purpose   :   assign key shortcuts when workbook is activated
        Application.OnKey "^+o", "PERSONAL.XLSB!PERS_FormatSelectionToNumberNoDecimals"
    End Sub

... to assign the shortcut key CTRL-SHIFT-O (O as in other; you may assign another key of your choice) to the macro.

=> whenever you need to re-format a range to Number with 0 decimals, select the range and press the shortcut key.

In order to get rid of the key assignment when switching to another workbook you may place

    Private Sub Workbook_Deactivate()
    ' Purpose   :   removes key short cut assignments if workbook is deactivated
        Application.OnKey "^+o"
    End Sub

...in my data workbook's ThisWorkbook module (VBA editor)