I managed to control my PS3 from my PC, with the method described at forums.ps2dev.org.
It only works with one of the 3 dongle I tested.
All are able to power up the PS3, but connection is aborted with the 2 dongles that can’t have their bluetooth device address changed permanently.
From my desktop pc that is located in another room, I pressed space key (cross button) to select the user, and right and left keys to navigate in the menu 🙂
Next step: install a linux distro on a laptop so as to make intensive tests in front of my PS3.