Yes, they are coordinates from the DxDesigner window. All the hard work is already done for you. Just stick with that and you'll be fine.
I posted the part about the difference between the mouse and the cursor only as a warning, because I once wasted a lot of time attacking the "mouse" position the wrong way, when what I really needed was the cursor position. I hadn't realized there was a difference until then. Sometimes we use the terms as if they are interchangeable, when to the OS they are not.