My son has these allergies and many more. The whole food allergy cookbook is wonderful. Also RICE milk is a great substitute for milk in any recipe. There are also egg-replacer powders if you find out he is allergic to eggs as well.
Shop whole foods and natural sections of grocery stores..there are tons of products out there dedicated to allergy free eating. Also go to allergygrocer.com. A great product line free of common allergens is 'Enjoy Life'
There is also RICERA yogurt that is milk and soy free and contains lots of calcium.
I have lots of advice if you are interested. my son is allergic to milk, soy, eggs, peas, tomatoes, chicken/turkey, beef, lentils, chickpeas, fish and a few fruits...yes, really. He lives on bananas, raisin bran, oatmeal, sunflower butter, pork, pasta and some veggies.