We would like to offer a store-wide promotion to our customers but we do not want it to affect the amount payable to our vendors. The payable balance to our vendor should be calculated on the amount before a promotion is applied instead of after. The promotion would be taken from the store administrator's commission instead. Is there a way to accomplish this?
Admin commission = 10%
Promotion = 5% off order
Order value = $100
Promotion value: $100 * (5%) = $5
Amount due to vendor: $100 * (90%) = $90
Commission collected by admin: $100 * (10%-5%) = $5