my $balpar_re=qr{
        (
          \(                                 # opening (
            (?:[^'"()]++                     # Not a ', ", ( or ) - no backtracking
# incorrect              |(?:'(?:[^']|\')*?')           #' a single quote string
# incorrect              |(?:"(?:[^"]|\")*?")           #" a double quote string
              |(?:'(?:\\'|[^'])*?')           #' a single quote string
              |(?:"(?:\\"|[^"])*?")           #" a double quote string
               |(?-1)                         # must be a ( or ) so recurse
            )*+                              # zero or more time - no backtracking
          \)                                 # closing )
        )
        }x;

##</code><code>##

#!/usr/bin/env perl

use Data::Dumper;
use strict;
use warnings;

my $string=q{INSERT INTO sample_table (first_name,last_name) VALUES ('John','Doe'),('John','Smith'),('Foo','O\'Bar'),('Baz','D\'Qux (II)'),('(and so on, ','and so forth);');};

my $balpar_re=qr{
        (
          \(                                 # opening (
            (?:[^'"()]++                     # Not a ', ", ( or ) - no backtracking
              |(?:'(?:\\'|[^'])*?')           #' a single quote string
              |(?:"(?:\\"|[^"])*?")           #" a double quote string
              |(?-1)                         # must be a ( or ) so recurse
            )*+                              # zero or more time - no backtracking
          \)                                 # closing )
        )
        }x;

$string=~ s{$balpar_re}{mung($1)}ge;
exit;

sub mung {
    warn Data::Dumper->Dump([\@_],[qw(*_)]),' ';
    }

##</code><code>##

@_ = (
       '(first_name,last_name)'
     );
  at perlmonks.pl line 25.
@_ = (
       '(\'John\',\'Doe\')'
     );
  at perlmonks.pl line 25.
@_ = (
       '(\'John\',\'Smith\')'
     );
  at perlmonks.pl line 25.
@_ = (
       '(\'Foo\',\'O\\\'Bar\')'
     );
  at perlmonks.pl line 25.
@_ = (
       '(\'Baz\',\'D\\\'Qux (II)\')'
     );
  at perlmonks.pl line 25.
@_ = (
       '(\'(and so on, \',\'and so forth);\')'
     );
  at perlmonks.pl line 25.