... except, I have no idea what they used to do it with.
The program I use allows you to remove a license from one machine and restore that license on another machine after you've contacted the manufacturer and given them the new serial number. He then sends back a new registration number to tie the old license to the new serial number. The software is leased on an anual basis, so the licensing on the new machine will expire when it's supposed to, rather than the clock starting all over again.
Not sure if this is what you're looking for, but it's worth a shot. You can contact David at Argus Development and ask him how he accomplished the licensing routine he uses in ShowPro. He's a pretty good guy, willing to help with anything. www.argusdevelopment.com
...