Actionscript 3 :: Load The Last Text File From A Directory?

I have this function that loads an specific .log file:

function loadTracks():void {
tracksLoader.load(new URLRequest("/Users/Me/127.0.0.1,"+_logNum+".log"));
}

The logNum variable gets its value, writing it by hand in a separate text file, avoiding to open and editing the .fla each time the new .log has a different name:

logNumLoader.load(new URLRequest("/Users/Me/trackLogNum.txt"));

Some application creates in each session a new .log file with this file name pattern: 127.0.0.1,NUMBER.log // Being NUMBER the 5 digit changing part of the name, each time a new .log file is created. The newer the file, the higher this value is. how to make this script to autoload the last .log file, as it has the highest value in its name.