If you can feel the scratch with your nail you cannot buff it out.
Bring it to a professional detailer who knows how to wet stand and polish using touch up paint.
Go to a professional body shop to do it the right way.
Unfortunately, those are your only 2 options aside from leaving it alone.
Only way to know if you can polish out window is try using a machine, which brings me back to my original point, seek out a detailer. (I'm not talking about the guys at the car wash, but a professional who does "paint correction and high end detailing").