XML : CORS path change in Ajax

I have a Ajax post that renders a page that is on a different URL, the page it renders (on a server i have access to) has a java script function that points to a xml file as so

      $(function() {                  var test = new Test({                         XMLFile: "stage/tests/Inductive/exam.xml",                  });    

Problem happens within the Ajax render, I need the XMLFILE path to be

  http://siteA/stage/tests/Inductive/exam.xml    

if I try this as the Ajax renders this page I get

  https://siteB.com/http://siteA/stage/tests/Inductive/exam.xml    

My question is how do I point the XML path to

  http://siteA/stage/tests/Inductive/exam.xml