Hmm..
When I have unstand it right, you have 2 options:
1.)
Create your own form with a timer and show the counter there.
At the end you execute the shutdown...
(using:
https://docs.microsoft.com/en-us/win...down-functions)
2.)
Use then 'shutdown' batch-command:
https://www.cnet.com/how-to/put-a-sh...-this-command/
Both have a timer until shutdown...
Non off them have a regitry entry..