Setting Radeon Powerplay on when on AC ?!?

[beeblebrox]

Folks,
currently I am stuck with a T40 series model which, of course, is running hot. I installed all software discussed here. CPU is fine (undervolted), but the ATI GPU is running hot (50-60°C) when I turn off the fan. I hate the fan. Reducing GPU speed is worthless, has no effect.

I have read many threads here, but could not find a solution to ENABLE ATI powerplay when the notebook is running on AC.
Powerplay reduces voltage and drastically lowers the temperature. I am running Word and Powerpoint and there is no need for any graphics power.

Any quick solution out there for me?