php auto generate code on the same file
===

The following code generates a new php file playlist.php which contains the code as in $start $result variable
  
    $path = "./files/";
    $path2="http://".$_SERVER['SERVER_NAME'].dirname($_SERVER["PHP_SELF"])."/files/";
    //echo $path2;
    $folder = opendir($path);
    $start="<asx version='3.0'>\n<title>Example ASX playlist</title>";
    $Fnm = "./playlist.php";
    $inF = fopen($Fnm,"w");
    fwrite($inF,$start."\n");
    while( $file = readdir($folder) ) {
     if (($file != '.')&&($file != '..')&&($file != 'index.htm')){
     $result="<entry>\n<title>$file</title>\n<ref href='$path2$file'/>\n<param name='image'     value='preview.jpg'/>\n</entry>\n";
         fwrite($inF,$result);
     }
    }
    fwrite($inF,"</asx>");
    closedir($folder);
    fclose($inF);

I want to generate the same code in the same file which contains this code on a specified line number
is this possible ?