dadchamp is correct, you can just modify the "V3 Blank" .Cr2 file. Where the tweaking occurs is (unless the clothing is super skin-tight) you will run into issues with joint bends and the fall-off zones which is where Poser's joint editor comes into play (I'm not sure how Toolbox handles this).
And to a point it is a bit like HTML programming in that you have tags that tell the CR2 "This is the head" and "This is the neck" and parameters below each that tell it "The joint bends here" and so on. You model is just a static object. The CR2 tells Poser and DAZ Studio how to manipulate it and where the material zones are applied and how.