A dietician treating my eldest daughter told me that roughly a third of people with cows milk allergy also can't tolerate soya. but there are plenty of alternatives as mentioned by 4get and 237SJ. Allergies are different to intolerances - my daughter is allergic to cows milk protien which is different from being lactose intolerant. If you're trying to completely eliminate cows milk from your diet, look very closely at food labels it's in all sorts of things that most people don't realise eg. processed ham!
Calcium can be found in lots of other foods eg. leafy green vegetables (google for a list)