do you mean you are changing the very texture that you are using?  that's pretty cool.  if you save that texture in your editor the pz3 should pull up the saved one(the pz3 always seeks textures on opening...just try not having one!...no actually, don't to that).  if you are renaming the textures, then just resave the character, or make a mat file.  i haven't done the mat file thing yet but i don't imagine it's too tough.  i just bough texture converter which is supposed to do that to today, but haven't tried it.  there are certainly things out there for that though.  i think even some freebies and possibly a python.