I am trying to create a progress bar for DH souls. Similar to holy power for Paladins however souls is not considered a DH power. It would be nice if I could use a condition to control the fill of the bar in order to do this.

ex. If the souls aura is = 1 stack then fill the bar to 20%

If there is a documented way to do this currently either through the built in features or through custom lua please let me know.

That's done by writing a custom trigger.