I use
PHM RegEdit
It's not that hard if you know what you're looking for. If you get lost, though, it can be intimidating.
The Paths can be found in
HKEY_LOCAL_MACHINE>Software>HTC>Biotouch>APLaunche r, CustAPLauncher, CustAPLauncher2, and CustAPLauncher3
Each of those folders have App0-App7
Each App folder has a parameter called "Path" where the location of the executable is.
For instance, the GoogleMaps button can be found at
HKEY_LOCAL_MACHINE>Software>HTC>Biotouch>CustAPLau ncher>App1
Find where your GoogleMaps.exe is located on your phone, then type that location as the Path.