How to control a shape key driver with Python

Hi all.

I have a mesh in my scene, with some shape keys. I added another mesh that acts as a driver (basically, rotating this driver on its Z-axis will apply the relative shape key to the other mesh).

Everything works fine in 3D view, but if I rotate the driver in BGE nothing happens.
I searched a lot for a resource/tutorial on how to control shape keys drivers in BGE with Python, but found nothing yet.

Any suggestion?

Thanks in advance