there is already a option in Knight Online for taking any screenshot whenever you want. You can use it with the '' - '' it's totality on the right side of your keybord between the * and + at the number place.
http://oi61.tinypic.com/28vd84w.jpg Red spot.
When you finaly find it and pressed on it you can go to Computer>Programs Files>MAXKO>Titan> And Search ''KscViewer'' open it.
Now there will be a lot of files with that name '' 2014_9_28_14.18.46.ksc'' (depending the dates when you took it.)That long number its the screenshot you took from the '' - ''.
Go search the one that you wanted and when you found the one that you wanted drag it in KscViewer and your screenshot will appear.
But if you want it like a picture you should use PrtScrn for copy and past on paint/photoshop/gimp/ or whatever you using and save it.
But as you wanted if i understood what you really want. Its something like '' pressing on PrtScrn and your screenshot will be directly done somewhere in TITAN files without doing any effort to make the picture but you know what it's wont happen becoz it's kinda useless and it's a big waste of time for the Developper and they probably can't do it. So sorry but you have to make it from your own.
maybe im wrong but i dont think so.