How to summ loc + rot by driver

Hi
I work on tank rig, and i have a problem.
For simpe example
http://wstaw.org/m/2013/06/29/locrot.png
I want send value of circle Z rotation and Y location to X rotation of cube
Ho to do that by driver?
the scene file https://dl.dropboxusercontent.com/u/34973756/loc%2Brot.blend
Thank you

UPDATE
Transfoem Space don’t give right resoult
http://wstaw.org/m/2013/06/29/locrot1.png
https://dl.dropboxusercontent.com/u/34973756/loc%2Brot2.blend
Because it stop rotating after circle turn on 90 deg (i need local space)

UPDATE2
I dont know why tis driver
http://wstaw.org/m/2013/06/29/locrot2.png
https://dl.dropboxusercontent.com/u/34973756/loc%2Brot3.blend
translate not only location that i set
it translate rotation of circle too
Why?

[SOLVED]
I should be add a global parent.
With regards
BROTHERMECHANIC