# inefficiently sort by descending numeric compare using
    # the first integer after the first = sign, or the
    # whole record case-insensitively otherwise
    my @new = sort {
        ($b =~ /=(\d+)/)[0] <=> ($a =~ /=(\d+)/)[0]
                            ||
                    fc($a)  cmp  fc($b)
    } @old;

    # same thing, but much more efficiently;
    # we'll build auxiliary indices instead
    # for speed
    my (@nums, @caps);
    for (@old) {
        push @nums, ( /=(\d+)/ ? $1 : undef );
        push @caps, fc($_);
    }
    my @new = @old[ sort {
                           $nums[$b] <=> $nums[$a]
                                    ||
                           $caps[$a] cmp $caps[$b]
                         } 0..$#old
                  ];

    # same thing, but without any temps
    my @new = map { $_->[0] }
           sort { $b->[1] <=> $a->[1]
                           ||
                  $a->[2] cmp $b->[2]
           } map { [$_, /=(\d+)/, fc($_)] } @old;