QAT Undo & Redo Controls

Hi!

I'm trying to recreate just a few of the built-in contols in the QAT. I've been succesful with all of them except with Undo and Redo. The Ribbon Control List states that the Redo and Undo controls are gallery controls but when I use the <gallery idMso="Undo"> or redo I get an error warning from Custom UI Editor For Microsoft Office.

I'm wondering what's the correct way to do this.

Thanks in advance.

Bert