apply coupon to orignial price, not discounted price

-- HikaShop version -- : 4.0.1
-- Joomla version -- : 3.9.1
-- Browser(s) name and version -- : Firefox 61.0.2

I would like to have a coupon applied to the original price before the discount is applied. In other words, if the product has a discount, ignore the discount and apply the coupon. It seems from the documentation that you can set it to ignore the coupon is the discount applies, but I want the opposite.
For example:
User group XYZ gets a 20% discount for certain products. This discounted price is shown both on the product page and in the cart.
We are also doing a promotion for 50% off the ORIGINAL product price for certain products for XYZ users.
So if a product is $100. When the user logs in, the price on the product page and in the cart will show the 20% discount applied, $80. If they enter the coupon code, we want the total to be $50, not $40.

Hi,

I don't see a solution with the options available by default in the coupon system.
As you said, the system applies the coupons on the prices after the discounts are applied.
Maybe AwoCoupon allows for that ? awodev.com/products/joomla/awocoupon
However, it's not mentioned the compatibility with HikaShop 4 on that page, so I'm not sure if they didn't get to it yet or didn't update that page, or if they don't want to support HikaShop 4. You'll have to check with them on that and on whether it can apply coupons on the undiscounted amount.
The last possibility is to have a small HikaShop plugin developed to recalculate the coupon the way you want.