Display a countdown message to remote computers via Powershell

I'm working on a script that will eventually do all of the following:

1. Send message to premade list of computers, informing them that in X seconds a program will close so the database it attaches to can be updated
2. At the end of the time, force close all instances of said program on each computer
3. Copy over updated database from testing location to live
4. Re-open the program on each computer (they automatically reconnect to database)

I need the message to both show a live countdown, and to be unable to be closed by the user outside of killing it in task manager. I can send a msg easily enough, but that allows users to accidentally close it (or purposefully...). From what I have tested out, I really like the output that Write-Progress gives, but I do not know of any way to have that same output show on the target systems

Function...