Variables in a script for DMN-Input



so I know that it is possible to set variables in a Script-Task with the following statement:

execution.setVariable("name", variable);

Now I am wondering if it is also possible to declare variables in a script for a DMN-Table-Input:


I tried something like this to create a new variable in the script and use it as the Input Variable. But this does not work and always sets the value of the variable to null.

And using execution.setVariable or task.execution.setVariable is also not working at this place. Am I missing something or is it a desired behaviour, that no new variables can be used at this place.