Invoice Request ( Total Pricing )

Hi Experts

I have a situation where I want to refine the invoice items during my project invoice request process.

I know you are able to add further components within the Item Price section of the screen such as Goodwill, Surcharges, List Price etc. You also have the option to add further components within the Total Price section of the screen at this stage I only have 2 options Overall Discount and Restocking Fees. Is it possible an extra option. I'm wanting to add in a "Surcharge" line for the entire invoice.

Thanks in advance

I have attached a .png file

Antonio