[Boost-users] boost program options positional arguments in config file?

I've been using program_options quite happily and successfully for a short while now and would like to take this opportunity to express my gratitude. Is there a way to extract postional args from config file, though? The headers seem to indicate that it's possible include_positional flag, but I haven't been able to find something workable in the documentation or mailing lists. Thanks, Zak