Put macros A, B and C somewhere on action bars.
Distilled wisdom from Wowpedia's "Making a macro" page.
Then make a new macro,
Code:
/click [btn:1] A; [btn:2] B; [btn:3] C
btn1=left click; btn2=right click; btn3=middle click
You can remove any of these, or add more conditionals as you like (use modifiers to change selection for when using keybinds, etc - see the link above for details).
The tricky-ish part is what to call A B and C - you don't use the macro names, you use the names of the action bar buttons where you put the macros:
- ActionButton# ......................... Main Bar*
- BonusActionButton# ................. Dynamic bar that switches actions based on Druid Forms, Warrior Stances, and Rogue Stealth*
- MultiBarBottomLeftButton# ........ Bottom Left Bar
- MultiBarBottomRightButton# ...... Bottom Right Bar
- MultiBarRightButton# ............... Right Bar
- MultiBarLeftButton# ................. Right Bar 2 (to the left of "Right Bar")
- PetActionButton# ..................... Pet Bar
- ShapeshiftButton# ................... Druid Forms, Paladin Auras, Warrior Stances, Death Knight Presences, Rogue Stealth, Hunter Aspects
For instance, ActionButton1 is the main action bar, button 1; MultiBarBottomLeftButton1 is the button immediately above that one in the standard UI; you can figure out the rest.