Custom made wyUpdate.exe exchanged for original during update

I have rolled my own custom stand-alone wyUpdate.exe (which I call Updater.exe) using the open source code.When running Updater.exe from my program, it automatically exchanges itself for the original wyUpdate.exe (this time called Updater.exe). I guess this is what is referred to in the documentation as "wyUpdate self-updates"?After the upgrade I have the original wyUpdate.exe (disguised as Updater.exe) in my program folder.

How can I have my own Updater.exe during the update process and also in the resulting program folder?

Thanks!Sven