for my $line (@lines)
{
    for my $replace (@replaces)
    {
        my ($s,$r) = $replace =~ /\\replace\t(.+?)\t(.+?)\n/
            or next;

        $line =~ s/\Q$s\E/$r/g;
    }

    print $line;
}

##</code><code>##

for my $replace (@replaces)
{
    my ($s,$r) = $replace =~ /\\replace\t(.+?)\t(.+?)\n/
        or next;

    s/\Q$s\E/$r/g for @lines;
}

print @lines;