Can Non-dairy Creamer Be Used To Replace Milk How Much Milk Do I Put With Non-dairy Creamer To Make A Dairy Creamer?

How much milk do I put with non-dairy creamer to make a dairy creamer? - can non-dairy creamer be used to replace milk

I have a recipe for an iced cappuccino requires a kind of cream. However, I can use the cream, we have today. (My stepmother is crazy) on coffee

Even if you do not just put a little powder a little cream ordinary milk. But my question is: What proportion of non-dairy milk?
Or I should do something other than milk.