How do I tell gem to always get the MSWin32 version, if one is available?

If anyone could help me out, I'd appreciate it.

When I do a gem install or gem update, if the latest version is available in both ruby and mswin32 versions, I'd like to automatically choose the win32 version. I looked in the command line options and in the docs for the gem config file, and I can't find anything. It's obviously not a big deal, but it would be nice.

Thanks in advance for any help.

Mike