Silk Java: in IE11 code to press button "Do you want to open or save ...jnlp"

I am making a test-script in java that verify that "example.jnlp" can be open in IE11 , this is the requirement. TestUser are NOT administrator right for IE11, then when script run there is this Control-Panel in IE11 "Do you want to Open or Save example.jnlp from server-XXX":
But how access and press this Open button, it seems that this UIcomponent is not a standard one... some MS-security-UIcomponent.

private void openApp() throws Exception {
   log("preparing browser");
   BrowserBaseState browser = new BrowserBaseState();
   browser.setUrl(LoginProperties.getInstance().getJnlpUrl());
   log("preparing execute browser on desktop");

   // problem here --> "Do you want to open or save" --> cannot press open button

   browser.execute(desktop);
   log("application opened");
}

A silk capture show "//Control[@windowClassName='DirectUIHWND']", but how to use it?