Please forgive my lack of knowledge of Chinese. I'm doing book research and am looking for the most appropriate word for 'proxy' in the sense of a substitute or surrogate. For the sake of clarity, let's say you wanted to kill someone, but wanted someone else to do it for you. (I'm not looking for the word for hitman or assassin; it needs the above connotations.)
替代 seems to be the closest I've found, but I want to avoid any confusion or the meaning being misconstrued!