OK then, I emulated the proximity sensor with the "Light Level" sensor (0,0), which is not that reliable but works more or less.
I have now these two Profiles:
1. Light Off
State Light Level [From:0 To:0]
Enter Task: LightOff (just switch the global var %Light to 0)
Exit Task: LightOn (just switch the global var %Light to 1)
2. Display Off
State: Light Level [From:0 To:0]
Enter Task: DisplayOff (waits 5 sec., checks if %Light is still 0 and switches then off the display)
I needed another switch then, to switch off (toggle) this profile when it is dark, because the Light Level 0 sensor triggers then sometimes, switching my phone's Display off while on the phone. So I have a Task-Button on my homescreen where I can toggle the "Display Off" Profile (Action Profile Status).
Amazing: I have a fast and mighty high tech phone where I can program a lot on it, but not such simple and basic things. Such makes me dream of a rooted phone again (stopped to root my phone some years ago).