pbuffer & render texture & multi-sample

Hi, all,
I modified codes of a 3D engine, redirect its output to a pbuffer, warp the images and put them to the screen. So, I’ve to select a pixel format which supports pbuffer and render texture. Now, I want to enable multi-sample in the pbuffer. But I failed to find a pixel format. I use Geforce6600 with ForceWare 77.72.
Is there any way to do anti-alias in a pbuffer which supports render texture?
Thanks a lot.

It work great for me on my GeForce 6600 and the latest NVidia driver. In my case, I dont bind the render texture to the pbuffer, I just do a copyTexImage from the pbuffer to a texture.