It would not work. Baking soda is quite basic (getting up near the most basic you can handle without some amount of pain). Combining it with cocaine hydrochloride breaks it off its acid base and turns it into freebase. This is how crack cocaine is formed.
Baking powder is a buffer. It takes whatever is added to it, acidic or basic, and brings it towards neutral. This would probably not form the freebase.
As others have said, just go buy more baking soda. You can often even get a small, off-label box at dollar stores that will work fine.