Warrior macro help - Conditonal #showtooltip

I have the following macro:

\#showtooltip

/cast \[mod:alt\] Master Strike; \[stance:3\] Battle Stance; Overpower

This macro will cast Overpower If im in battle stance or switch to Battle Stance if im in Berserker Stance, or cast Master Strike if Im holding alt.

What I'm unable to achieve is, while in Berserker Stance, I want it to show Overpower tooltip icon Instead of Battle Stance Icon (while not holding Alt key).

Edit: Using CleveRoid