#!/usr/bin/perl

$teststr="blah,blah(blah,blah(blah,blah(blah))),blah";

#This is three elements: 
# blah
# blah(blah,blah(blah,blah(blah)))
# blah
# I don't have to worry about escaped parens, the file format forbids it.

foreach (&parse_comma($teststr)){
  print "$_\n";   #This just proves that it works
}

sub parse_comma{ 
  my $commastr=shift;
  my @tags;
  my $count=0;
  my $carrystr="";

  foreach (split(/,/, $commastr)){
    $_=$carrystr.",".$_ if $carrystr;
    $count=s/\(/(/g;
    $count-=s/\)/)/g;
    if($count){
      $carrystr=$_;
    }else{
      $carrystr="";
      push @tags, $_;
    }
  }
  return @tags;
}