powdered milk

I’m thinking of using powdered coconut milk. If liquid it would replace water, so I assume that as powder form it would not. Yet, how to establish how much to add? Can you help me here?

Hi, beautiful people! I wanted to try out a soap made with honey, oatmeal and dried milk powder, but I could only find coffee creamer (Nestle Coffee Mate). I live in a rural village, so some items are hard to come by. Will the coffee creamer do the trick or should I wait until I get my hands on...