Coupon Applied To Total (including Shipping)

I have created a coupon with the following aspects.

Function: Coupon
Function: Product
Amount
$50
Number of Uses: 1 Total
Minimum: Blank
Discount: Overall
Start Expire: Blank
All Customers
All Products

I need the $50 to apply to the total of product cost and shipping. If I have a product that totals $45.00 and the shipping is $10.00 I need the Coupon to apply as $50 off of the total of $55.00 (total plus shipping).

In my testing so far... if the product total is $45.00, the discount is only $45.00.

What setting do I need to make so it applies the the full total?

Thanks in advance!
RedShop + Joomla 2.5

Ok, there are 2 ways to get shipping costs included in the discount:

1) Function type gift certificate (not choosing any products/categories). This will discount the product total as well as the shipping. If there is any remaining balance the customer will be able to come back and use the gift certificate until it reaches 0.

2) You would have to create a parent coupon
Coupon A: coupon discount on products
Coupon B: shipping discount on shipping
Coupon C: parent coupon where you add Coupons A and B and join them together with 'All that apply'