Hello,
I'm not a Windows Perl guru, but I have worked a very little bit with the Win32 perl library. I took a look at your test suite last night and started modifying it to work in Windows. You might want to take a look at the Win32 perl modules, if you haven't already. You can find them at the Activestate website. More specifically, check out the Win32:API module. This module provides a "call" method which is very similar to the "call" method in wine.pm. AFAICS, this module provides everything you need to run your extension in Windows (with slight modifications). This module is not included in the standard ActivePerl package, but you can get download it at http://www.activestate.com/PPMPackages/5.6/Win32-API.ppd. You might consider rewriting your extension into a Linux port of this Win32 module.
HTH,
Joshua Thielen