Excel 2007 : adding custom button to quick access toolbar

I just entered the world of excel 2007 (and win7) kicking and screaming.

I have a macro that I want to add as a button on the quick access toolbar. I would want this macro to be available from the QATB (is that what yall call it?) anytime that I open excel.

How would I go about doing this? BTW - it doesnt really matter where the button is located just as long as I can have super fast access to this macro (actually I have many many I want to add).