Remove Selected Categories from Discounts / Trade accounts

We sell a range of items that we do not want to offer discounts on but there are too mant to individually select when setting up discount codes. We have a subscription members club and so we issue members there own discount code to use online. They cannot use on things like PDFs, Gift Vouchers, and other items we may not want discounts on. I was hoping the Trade option would allow you to remove categories so that we can give members their own login access with the discounts applied, but as the discount is automatic it deducts on gift vouchers etc too.