getelementbyid, html, container and createjs - how one can struggle?)

from noob in this field (flash animator trying to learn some js).

hi all.)))

for the learning purposes: how i can change/modifiy codepen/jsfiddle examples, to work from inside animate cc? i mean, almost every such example use html+css+js file, but animate cc produce his own files, that i don't want to modify, for many reasons, so "getelementbyid" is not a solution here. this may be "stage" with "addchild"(am i right?), but what if i need to put some example inside container (movieclip) on timeline? createjs makes his own limitations and code snippets is for sure not enough here...(((