"EDIT: I found the solution! There is one function called "H/W" which seems to be "hardware". I fyou choose this, you can set hardware-switches insted of only functions.
Thanks for helpin myself :-)"

"Seem like things have changed with the new T8FG firmware. In Prog.-Mix page 2 has changed. I only can choose from functions (e.g. throttle, rudder, ailerion...) but not switches like "SF". Any idea how I can get it done anyway?"