Excel Add-in Registry Location XLA

Excel XLA Add-in information is stored in the following registry key locations.

If the add-in has been added and ticked to run :
HKCU\Software\Microsoft\Office\versionno.\Excel\options

If the add-in has been added but not ticked to run :
HKCU\Software\Microsoft\Office\versionno.\Excel\Add-in Manager

There is more detail on this plus automation and Com Add-ins on this link :
http://www.excelkb.com/article.aspx?id=10193