I have 14 items on my store. Five are listed as individual items and nine are listed as Combos. The combos are various combinations of the five individual items. Specials is used to give a 5% discount on the combos. I applied a salemaker discount of 10% to the entire store as a preseason special. I chose "Apply sales deduction to specials price-Otherwise apply to price".

I want the combined discount on the combos to be 15% of the full price. Zencart calculates the selling price by first taking the specials discount and giving the specials reduced price, then taking the salemaker discount off of the specials reduced price.
((full price*.95)*.90)= discounted selling price. The discount is listed as 15%. The actual discount from full price with this calculation is 14.5%. On higher dollar items this makes several dollars difference.

What I need is for the combined discounts to apply to the full price.

What needs to be done to make this change?