right clicking a target is VERY hard as WoW isn't a directly scriptable application hence why "system events" is called.
Aswell as that I can't find a mouse click function (i use bbs.applescript.com for all my AS stuff)
there is an extras suite that works with AS to produce mouse clicks on a currently selected GUI target how ever I'm not 100% sure it would work in WoW (infact i doubt it would)
I am currently working on a very simple WoW bot for Mac in xcode but it being more of a pain in the arse than i anticipated, will keep you updated.