Adding a new sub-total field

[marnslee]

I need another subtotal field in the orders/invoices so that people can see the amount of the order before any discounts are applied, can someone steer me in the right direction please.....

 

at the moment it looks like

 

Discount Coupon EG01 applied: -$72.90

GST not applied: -$7.30

Sub-Total: $187.10

Shipping: $0.00

GST: $17.01

Total: $187.10

 

but i need

 

Gross order inc GST: $267.30

Discount Coupon EG01 applied: -$72.90

GST not applied: -$7.30

Sub-Total: $187.10

Shipping: $0.00

GST: $17.01

Total: $187.10

 

any help would be much appreciated