ActionScript 3.0 :: XML Read From Dynamic Or Web Location

I am working on a site which uses a flash menu I was handed. The flash menu uses an xml file to generate, it works fine as long as one stays at the top-level dir of the site, say [URL]. When someone enters a page, say [URL] the menu stops working, being unable to read the xml which is hardcoded to be in the same directory as the page it's called from (menu.xml is in /).

I must say that the locations visible to the browser are not real, everything non-top level in [URL] is just mod-rewrite, thus none of the directories test or page really exist. I can see the reason why flash looks in the same directory as the one the client requested for the file (instead of looking at the same dir locally in example).

So the two solutions I thought of:
1. Is there a file_exists function i could use to make the flash recurse upper-level directories until the menu finds the xml file? as in:
var menufile = menu.xml
while (!file_exists(menu.xml)) {
menufile = '../' + menufile
}
Obviously this is not real code

2. Is there a way to open the xml from a web location and not from a static path relative to the swf itself?