while(...){
    chomp;
    if (m{([[:digit:]].+?);.+?$tags[0].+?=.+?((-)?[[:digit:]].+?)$}s) {
        printf "%s,%s\n", $1, $2;
    }
    ....
  }

##</code><code>##

  why use '.*' after $2 i.e (\-?\d+.?\d*).*/. Your code will still have worked as (\-?\d+.?\d*) for your $2.