Fine Tuning D700 24-85 3.5 lens

Hi Guys, just bought the above lens and a little soft wide open at 24mm, where is much better wide open at 85mm. my question should I try fine tuning at the 24mm mark and would it effect the focus at 85mm? Anybody done this please let me know your results, and how you did it. What do you save it under?
I dont have any experience fine tuning zoom lenses. Many thanx,
Ray.