I see you are on Bome MIDI Translator Classic. I'm not sure if it supports various outgoing character sets but maybe you can try this if it doesn't recognize the keystroke directly.
Open the Windows Character Map tool. Look and see what the character code is. Then use the Windows Alt Code to type in the desired character.
On the US Keyboard [ is Alt(091) and [ is Alt(093) - Make sure you use the numeric keypad for the numbers.
I'm not sure what the character codes are on the German Keyboard
Hold the ALT Key down, then the type in 3 numeric keys, then release the Alt Key.
I know this works on MT Pro version but Classic Version might not.
Steve Caldwell
Bome Customer Care
Also available for paid consulting services: bome@sniz.biz