OK, so it will probably be an attribute of the $ppu object.... so in dataAssist you will enter something like: <?php echo($ppu->uploadedFileName); ?>
Now, I'm not sure if it is "uploadedFileName" or what the value is, since that information is probably in their documentation, or maybe they have Bindings available for it (that is how we would do it), or you could look for what you use referenced in: <?php require_once('../ScriptLibrary/incPureUpload.php'); ?>