If you send the order confirmation from the CMS, you can customize the columns on the order confirmation. Follow these steps in the CMS:
1. Go to Administration > Order Types.
2. Click on the order line.
3. Click on the blue 'Columns' button.
4. A window with 'Deactivated columns' and 'Activated columns' will appear.
5. To add a column to the order confirmation, drag the column from 'Deactivated' to 'Activated', and vice versa to hide a column.
6. Drag the active columns to the desired position to change the order.