ActionScript 3.0 :: Conversion From Static To Dynamic Flashvar

Would like to receive the flashvar "filepath=.$name" which contains a string which is the dynamically generated file path to xml file. I would like the flashvar to replace the "xmlfile.php", which is the file playlist.load opens. E.g.
playlist.load("xmlfile.php"); works with this
playlist.load(flashvar); would like this if possible or the equivalent

The file loads the xmlfile.php correctly and will read and play files, I would just like to make this
"playlist.load("xmlfile.php");
" load the flashvar.filepath (contains file path).

var myflashvars:Object = this.root.loaderInfo.parameters;
for(var s:String in myflashvars) {
playlist.load = (myflashvars[s]);
}
//Passing the flashvars;
<param name="bgcolor" value="#ffffff" />
<param name="flashvars" value="<?php echo "filepath=".$listxml; ?>" /></object>