Sorry but Your reply tells me nothing. You think of something, a way to do things, that I don't catch.
"Telling the IDE" is done by the Pc keyboard as I think and the IDE outputs the Pc strikes to the controller that's reading using Serial.read.
The controller can send text to the IDE using its serial monitor and it can be viewed on the Pc screen.
Just do what You think of and show how to do it.