When we send back the Reg Event for COM Add-Ins and Automation Add-ins we populate the Name and the LoadBehaviour, but not the Path. This path is will be held in the registry.
Doubt Windows has a method to give us this, but the logic should be fairly easy to replicate, searching HKLM and HKCU Classes and CLSID, taking into account whether we are running inside 32 or 64Bit Excel.