Changing MATLAB_SHELL not from startup file has no effect on used shell

Hello,

in my application I want to exchange the used matlab shell with a script which is run upfront before executing the actual command because we have a module system and I don't want every user to activate the needed modules every time before starting matlab. For that I've written a shell script which is set in the startup.m file as the MATLAB_SHELL variable. Now everytime when I run matlab from that folder everything is working properly. Now, I would like to let the user to start MATLAB from every file system location and then let him run the matlab command "run /path/to/aplication/startup" which should also set up the MATLAB_SHELL variable, but exactly this behaviour is not happening and a normal shell is run. can someone explain how to achieve the desired functionality?

Best regards and many thanks in advance,

Nikita