I didn't test it, but you may want to try to use the option --exclude-module=MODULE from the pp to not include the Win32:: modules.
Check the pp documentation that comes with the ActivePerl that, for some strange reason, is on the Pragma section (on my ActivePerl 5.8.8 rev 820, at least).
Alceu Rodrigues de Freitas Junior
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"You have enemies? Good. That means you've stood up for something, sometime in your life." - Sir Winston Churchill