Hey Csaba,
I understand that you want to use external C/C++ code to import certain variables to be later used by Data Store Memory block.
In order to use the global variables defined in the external code, the recommended practice is to use a Stateflow chart in order to call your function and to access the variables. You would need to write C/C++ code in the chart so that during simulation, the model reads and writes to the variables. These global variables can be converted into MATLAB variables and then used to initialize Data Store Memory block.
Once you can access the variables defined externally, you can use them to modify the Data Store Memory block.
For more information upon accessing the variables from an external C/C++ code into your Simulink model, refer to the "Import External Code into Model" section of the following documentation: https://www.mathworks.com/help/rtw/ug/generate-code-for-interfacing-data-with-external-code.html#:~:text=Integration%20Workflow.-,Import%20External%20Code%20into%20Model,-To%20exchange%20data
I hope this helps!
