Is there a simple way to find where an application has been installed by the Office Developer?

When I deploy a package, the user is given a chioce of accepting the default location, or selecting somewhere different. Now, if I want to distribute an update, I need to determine where the original files have been saved by the user.

One way appears to be to look for the uninstall registry entry, but even there, the key used is not unique ("ODEUNST #n", where n is an integer), so it involves looking for all keys of that form (how do I do a wild-card lookup on the rgistry?) and looking at the application name, followed by parsing the uninstall string

Any suggestions would be much appreciated!