Animography Controller is a free tool that allows you to easily link all customizable features to a Null layer with just one click.
Simply select the the characters you would like to link to the controller and hit the 'Create controller'-button. The script will automatically create a Null layer with all the controls, duplicate the selected characters with linked expressions and places them in a new folder. Check out the proces in this short tutorial.
For more advanced features, please check out Font Manager.