This Order Total extension will add a new line item to the order, which is an intermediate total of the line items that come before it. It will not affect the final total itself; the new line item is for display purposes only. You can use this to show the sub-total + shipping, the total before tax, etc.
Upload and go — no core file modifications are required.
Set the status, sort order, and title of the line item directly within the extension admin panel.
Multiple languages and HTML are both supported within the line item title.