How to Window.open using cocoonJS?

Ok I need to make a browser call in my game, but Ludei people tell me that Window.open function nor C2 browser object has been implemented yet.

But they gave me this line to use that will do the trick for now.

ext.IDTK_APP.makeCall('openURL' , "URL" );

But I opened the C2runtime.js file to figure out how or where this can be used but it was like reading japanese for the first time for me.

Can anyone give me a hint on how to use this?.

Thanks!!