Probs. The bow itself could have a Demonomancy rune which would imbue arrows with an essence that is harmful to demons, even if the arrows themselves are mundane. Any particular type of bow you want it to be? Longbow for range? Short for portability? Maybe composite for compact strength? Or would you like one of Tyrael's exotic ones, the Bow-Staff? It's a bow. And a staff! Very sturdy can be be used for combat even while strung, but it requires a lot of strength to draw. You won't be doing any rapid shooting with it, that's for certain.