while (<IN>){
   next if /^#/;
   # extract $zip, leave line unmodified in $_
   ( my $zip = ( split /,/ )[ 2 ] ) =~ tr/"//d;
   
   if ( I want this zip code){
      .
      .
      .
   }
   else{ 
      push (@zips,$_);
      close(ZIPS);
   }
}