Because you have to write code to connect to MATLAB with EJS.
So you need to learn to use EJS.

I would suggest you install latest version of EJS, download the above jar file and double click to run it in your computer.
Right click and select [b]open ejs model[/b] to open EJS and learn how it was created.
And you can do similar thing with EJS 3.4 or earlier EJS version (which support MATHLAB).

I do not have any experience with EJS connect to MATHLAB, so you should learn EJS in order to do it.
And you can use the version I created as an example to learn it.
I will try to help when you learn to use EJS. But I would not be able to help when EJS need to communicate with MATHLAB. So you better learn to create it with EJS 3.4 by yourself. I think this is the best for you to do it by yourself.  ;D