Explain in more details please how we could do it?
I couldn't find the way (InMLU here you know )
KDE CC - Hardware - Power Management
First item on left ..... Energy Savings Settings
Last Item on page ..... Run Script
Tick the item, put the path to the script in the box, and select the number of minutes of inactivity before the script should run.
Make sure the script is set to run before any of the other settings kick in ..... I haven't tested it other than this way.