This should be easy for anyone but me

I have an invisible button with the following code:

on (release) {
	getURL(HERE_IS_MY_PROBLEM, "_parent");
}

My problem is I need the URL pulled in from an external .txt file so anyone can change the URL without opening Flash.

I know how to LOAD an external file:

loadVariables("download_url.txt", "");

And in my ‘download_url.txt’ file I have:

downloadURL=http://www.mydownloadurl.com/mydownload.exe

I would greatly appreciate any help in putting this all together!