center point (global) of sprite

Greetings,

I am working on a project where I have a bunch of sprites that I'm manipulating the scale, rotation, anchor point and position of.  

I need to get their original center point (not their current pivot point) in global coordinates after these transformations and am a little lost with the best way to do that.

I see worldTransform -- is that useful?   If there's an example or short snippet it would be really helpful, even just an avenue to look down. 

thanks much! 

zach