i believe the location is:
\\HKCU\Software\Microsoft\WindowsNT\CurrentVersion \Windows Messaging Subsystem\Profiles
if there are already keys called BlackBerryManager and BlackBerryServer on the target machine, you should delete them.
then copy all the .zdb files and .idm files from the old machine to the EXACT same path on the new machine. if it is c:\program files\common files\system\msmapi\1033, then it needs to be exactly that on the new machine.
then you can try to bring the BlackBerry Controller service up and try to see if it works.
if it doesn't work, then you have to start from scratch. launch the BlackBerry Manager, delete all the users. stop the controller and then delete and recreate the BlackBerryManager and BlackBerryServer profiles and reprovision the users. this will mean that the users will have to wipe and reactivate their devices.
hope this helps...and again...unsupported.