What wood are you working with. If the string is within the handle you should be OK. Pics are a big help so we can see what you are talking about.
Have you braced your bow to 3" to 4" or just pulled it to that much tip movement? If braced, forget the long string and work with it from that brace height. Are you planning on tillering your bow before reflexing it and sinew backing? You can straighten it out as you add reflex at the same time and then, once it is how you like it, add the sinew backing.