Found a gem of a program and it is free. Unfortunately for windows only and only Win NT, Win2000, XP or greater are supported. But if you have those, read on:
PoserPorter
One function, is a Poser content importer. Runtime zip archives can be dropped on the program and the program will extract all of the files automatically to their proper location inside up to three seperate Poser runtime folders on your computer.
PoserPorter also serves as a content exporter which can manufacture and package a fully functioning Poser zip archive which you can sell freely to others, or
offer generously as a free download for all to use. With the exporter, you just select a Poser Runtime folder and hit export.
So far, on importing, the current conventional zipped archive format of Runtime/Library/ etc. Older format such as Poser/runtime/etc may not all go where they are suppose to. I'm still experimenting.
Not real in-depth documents, but enough to get started!
Program last updated in Dec, 2005.
http://www.3dtrue.com/Poser/14.html
I dragged and dropped a zip file to Poserporter and it put the file into all three of my runtimes. You can also create new directories to zip into. Will export a single package or your entire runtime for archiving! Worth checking out.