The good news is there are many dairy substitutes like soy, rice, or potato milk. You can use soy and rice cheeses, soy or rice ice cream, coconut milk, and butter substitutes made from non-hydrogenated oils. Most of these can be found in your regular grocery store. Galaxy and Tofutti make a number of soy-based and rice-based cheeses, but you need to carefully check labels, not all are CF. For a butter substitute, we like Earth Balance Natural Buttery Spread which comes in sticks, like butter, or a tub, like margarine.
Soy is another item high on the allergy-intolerance-sensitivity list, but it is casein-free and if you want to try it, the Silk company has many soy milk options, one that is enriched with calcium and omegas. They also have smoothie drinks and yogurt. Whole Soy yogurt which has an excellent probiotic profile. There is a new rice-based yogurt called Ricera for those who are soy-free. Pacific Rice Milk has a pleasantly sweet taste and includes probiotics too. Until recently, Rice Dream had a tiny amount of barley added, but they have since gone gluten-free. However, check the label as this is very, very new and most stores still have old stock on the shelves. The Rice Dream must say "Gluten Free" in the long list of benefits. If it does not, avoid it. Vance's DariFree is a potato-based milk, you must mail order it, it comes in powder. Very economical if you order in bulk. It makes a creamy, "cow-tasting" milk. Several online places sell it, one source I like is http://www.allergygrocer.com/.