use Config;
    $PLATFORM = $Config{'osname'};

    if (($PLATFORM =~ /^MSWin32/i) ||
        ($PLATFORM =~ /^solaris/i)) {

        # use Perl 5.6.1 libraries
        BEGIN {

            @PERL_SHARE = (
                    "/foo/custom/perl/lib/Custom_mods5.6.1",
                          );
            unshift(@INC, @PERL_SHARE);
        };
    }
    else {
        # use Perl 5.005_03 libraries
        BEGIN {

            @PERL_SHARE = (
                    "/foo/custom/perl/lib/Custom_mods5.005_03",
                          );
            unshift(@INC, @PERL_SHARE);
        };
    }