You can't do reporting with Express. There isn't some trick to turn the free product into the paid product, and there isn't some obligation on Microsoft that they should have all the same features in the free and paid product. As you are saying, there's great value in those reporting features, and that's why people buy the versions that cost money. Just because Microsoft says you're allowed to sell the products you make with Express, they're not saying you can have any and all features in Express that you might use to make a product you will sell.
That said, you can probably get the versions that cost money for free. If you're writing software you intend to sell, if you make web sites for customers, or if you're a student (high school or college/university) then there are programs from Microsoft that give you free licenses of non-Express editions.
See http://programmers.stackexchange.com/questions/8055/can-a-developer-get-volume-discount-for-microsoft-products which has several answers that have nothing to do with "volume discounts" because they actually explain how to get the full featured product for free.