If you just want to do a specific part that's pitched, you can cut that audio part and load it into the exs24 sampler, create a new zone, choose your file..and then you can put where you want your note to start - I always use C1. Then your vocal sample will act like midi, and then you can keep using the sample and pitch it wherever you like. I'd only use this method for a little sample though, because it gets annoying when the sample is long.