Calling an object from external to root?

Hey all I’m pretty new to AS3 I was wondering how you would do this.

I have my main fla and then I have a actionscript named bullet.as

in the bullet.as I create a bullet using “this” throughout the script now how would I call the bullet on my main timeline?

I know if it was opposite I would use root.whatever but how do I go the other way?