As a non developer you need to find a developer to make a variant of the widget with your extra function in it. CKEditor supports plugins
Chris de Gelder
Giving back to there community here.
It seems impossible to directly interact with the CKeditor using the HTML or JaveScript snippet.
However, place the CKeditor in a container and you can interact with all elements in that container referencing the container's class name:
$(".mx-name-container5") // and write the rest of your code here
You can find the class name of the container by inspecting the element in the browser.