$file ="-(lala)-";
$skip ="-(lala)-";

print "$skip / $file\n";
if ($file =~ /\Q$skip\E/i) {     
print "matched!\n";
}

##</code><code>##

$skip = "-\(lala\)-";  # $skip is now -(lala)-

compared with

$skip = '-\(lala\)-';  # $skip is now -\(lala\)-