1. Select the column that you want to modify. You can do this by clicking on the column letter at the top of the sheet.
2. Right-click on the selected column and choose "Format Cells" from the context menu.
3. In the "Format Cells" dialog box, select the "Custom" category.
4. In the "Type" field, enter a single quote followed by the format code for the type of data you want to display. For example, if you want to display numbers as text, enter "'0" (without the quotes). If you want to display dates as text, enter "'dd/mm/yyyy" (without the quotes).
5. Click "OK" to apply the formatting to the selected column.

Now, every cell in the selected column will display its contents as text, left-justified with a single quote at the beginning of the cell. You don't need to manually type the quote in each cell - Excel will automatically add it for you based on the formatting you applied.