Shoes are props which can be parented to either P4 or Vickie, all you have to do is re-scale them, position them on the foot, set the parent to whichever foot you're working on, then save as a amart prop. Your manual will tell you how to parent and save as smart prop if you're unfamiliar with the proceedure. The very high heels for P4 that you're referring to also came with a morph for the feet to make them fit better -- you're on your own there. You could try to use the magnets to make them fit better, then spawn a morph target.