As Hans says.
Search this site for clone examples.
One of the main reasons you cannot dynamically create a symbol, is it is in effect a Scene within the main Scene and not a single element.
This means that anything with a Timeline or Actions, if duplicated/cloned will not inherit that functionality because the hype runtime and does not know about them from it's JS and other setting.
You can clone Hype Elements but there are caveats that you need to pay attention to or you will run into issues. Read the threads that mention cloning carefully taking note of how to avoid the pitfalls