It’s working via. the DefaultInput.INI. When I look in the Project-Settings I can see the entry. When I set Key to A for example it’s working with CTRL+A.
But your advice makes sense 
I try to find a Key for CTRL.
Update: OMG, that was easy thanks… I was to tired… I overseen the Left CTRL and Right CTRL Key in the Combobox -.- Now it works, thx.