Just so things are clear, what you want is a script to do the equivalent of UVMapper's import UVs function i.e. restore the grouping so that you can make morphs (as per -> http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2759444) ?
The easiest two languages to do this would be PERL or Python, but you'd need to install the standalone interpreters to use them from the command line (however a Python script could use Poser's built-in interpreter, but would need a simple GUI to collect arguments).

The other important thing is what location and naming convention do you want for the output files ?
Choices are :-

1. Add some suffix to the name, e.g. "-morph" in the same directory as the original
2. Put output files in a new subdirectory either in the original directory, or a new one at the same level but named appropriately, and with or without a suffix on the output files.