Hi Tom,

To add a digit to the front of a number in each cell in an Excel column, you can use the CONCATENATE function or the ampersand (&) symbol.

Here are the steps to add a "0" to the front of a 7-digit number in each cell in an Excel column:

1. Insert a new column next to the column containing the mobile phone numbers.
2. In the first cell of the new column, type "0" (without the quotes).
3. Copy the "0" cell by selecting it and pressing Ctrl+C.
4. Select the entire new column by clicking on the column header.
5. Right-click on the selected column and choose "Paste Special" from the context menu.
6. In the "Paste Special" dialog box, choose "Values" and click "OK". This will paste the "0" into each cell in the new column.
7. Select the first cell in the new column that contains the "0".
8. Type the following formula:
   Formula:

   =CONCATENATE(A1) 

   or
   Formula:

   =A1&"" 

   (where A1 is the cell containing the 7-digit phone number).
9. Press Enter to apply the formula to the first cell in the new column.
10. Double-click on the small square in the bottom right corner of the cell to copy the formula down to all the cells in the new column.

This should add a "0" to the front of each 7-digit phone number in the original column, resulting in an 8-digit phone number in the new column.