Did you try this option?
Configure > Select your game > Configure Wine > Tab Graphics > check Automatically capture the mouse in full-screen windows.
And if i were you i would change the desktop size to the game size.
MAD
P.S. I'm quite new to this software. So don't be suprised when its not the right suggestion to solve this. :-)
Edited by _MAD_
MAD stands for Mark aka Dark