if ($file =~ /-\(lala\)-/) { ...

##</code><code>##

my $skip = "/-\(lala\)-/";
if ($file =~ /$skip/)

##</code><code>##

my $skip = "/-\\(lala\\)-/";  # protect the backslash for itself
if ($file =~ /$skip/) { ...

##</code><code>##

my $skip = '/-\(lala\)-/';  # use singe quotes
if ($file =~ /$skip/) { ...

##</code><code>##

my $skip = "/-(lala\-/";  
if ($file =~ /\Q$skip/) { ... # quote it in the regexp

##</code><code>##

my $skip = qr/-\(lala\)-/;    # use precompiled regexps
if ($file =~ /$skip/) { ...