Exclude shipping from coupon discount

Hi, we are using coupons on our clients store, which work well. However, our client has asked for a tweak to how the coupon discount is applied. Can the discount applied exclude the shipping charge? For example, for 2 products totalling £30 with a £5 shipping charge, we only want the discount coupon applied to the £30 worth of products, making sure the shipping is always £5.

Kind regards, Phil