How to map mouse movement onto a G940 Joystick head

[oho]

I would like to map the mouse movement (for entering MFCD-buttons for example) onto my remaining G940 Joystick head (on top of the Stick). The head shows up in the list of axis and I can assign it to slew-control (but this doesn't work correctly by the way because it keeps on moving) but there is no line for mouse axis x and y to assign it (only a row as input device).

The Logitech software itself doesn't allow me to map anything on a mouse movement.

Any ideas ? Thx.