I am lactose intolerant. How can I prepare a good cup of coffee with milk? I don't like the taste of black coffee. I usually use soy-milk, but it is nowhere near original milk in taste.
Best option is lactose-free milk. I assume you live in India and it may be hard to find in India as lactose intolerance is not common among Indians. In that case, you may try goat milk which has naturally less lactose than cow milk. But I'm not sure if this will be enough (personally) for you.
Try frothing the soy milk with a hand-held frother, even if you just slightly froth it.
According to this Milk Frothing Guide
Incorporating air into the milk improves and sweetens the taste. Milk that has not been foamed at all tends to taste flat and dull by comparison.
Also consider experimenting with other kinds of milk substitutes: almond milk, almond-cashew milk, coconut milk, hazelnut milk, hemp milk, oat milk, and rice milk.