Coupon Minimum apply to specific products

[marcea]

I would like a Coupon where you can not only specify certain products that it applies to, but can also have the Minimum apply to the total of just those specified products. At present, the Minimum applies to the entire Shopping Cart, even products that are not part of the Coupon.
For instance, I want to offer 10% off XYZ company products, minimum $50 of XYZ products. Right now, we can limit the 10% to a list of products, but the customer could order $20 of XYZ products and $40 of ABC products, and get the $2 discount. But I want the discount to not appear until the XYZ products total is $50 or more.