Something

project xenocide/base
        : requirements
                <include>.
                <define>XENOCIDE_BASE_BUILD
                <define>XENOCIDE_BASE_EXPORTS
        ;
if [ os.name ] = NT
{
project xenocide/base
        : reqirements
                <define>_MBCS
                <define>_USRDLL
                <define>_WINDLL
        ;
}