loading flash variables

Hi,
THis is probably a simple question but I cannot seem to find the answer for it.
I’ve been trying to use a header with a flash movie. this header has to dinamically show the title and description of the blog.

this is the code I use in the swf movie, which is in a template folder inside content called mariposa.

losdatos=new LoadVars()
//losdatos.load("1.txt");
losdatos.load("https://www.mibabilonia.com.ar/mariposafuriosa/wp-rss2.php");

losdatos.onLoad = function(exito) {
if (exito) {
blogdescriptiontxt.htmlText = this.description;
} else {
//Mostrar mensaje de error en el campo de texto
blogdescriptiontxt.text = "Error!! :(";
}

The thing is: I don’t know which php file I should call in order to have the variables loaded in my text box, and also, I don’t know the variable names or where I can get them ??
so as you see, totally lost!
any ideas where should I start from?
I don’t want to modify the whole blog to use a flash skin, just make the flash find the variables.
thanks a lot for your help,
Indira