var fso = new ActiveXObject("Scripting.FileSystemObject");
var folder = fso.getFolder("C:\\ProgramData\\Objectif Lune\\PlanetPress Workflow 7\\PlanetPress Watch\\Documents");

for(var myEnum = new Enumerator(folder.files); !myEnum.atEnd(); myEnum.moveNext()) {
  var fName = myEnum.item().name;
  var ext = fName.slice(fName.indexOf(".")+1).toLowerCase();
  if(ext=="ptk"){
    Watch.Log(fName,2);
  }
}