How to have discounts on Fuel surcharge OTM

Is there a possible way out wherein once the fuel surcharge is discounted on shipment.

For example i having a shipment cost of 11.3 USD and Fuel surcharge of 2.2 USD to the total shipment cost would be 11.3+2.2 = 13.5 .

Now on the FSC cost of 2.2 we need to have some discount of lets say 10% so it 1.98 (=2.2 - 2.2*.10) so the total shipment cost should be 11.3+1.98 = 13.28 .

So is there any way where we can have discount on Fuel surcharge ..