There is a method of calibrating your camera using CS/CS2 at:-

http://people.csail.mit.edu/ericchan/dp/acr/

However ACR in PSE3 does not allow the calibrate tab.

Has anyone any thoughts on how this can be achieved in PSE3?

I don't know, I have a little bit of an issue with this idea. Capture will measure the light source and its qualities probably more-so than accurately rendering the card. Unless you shoot the card in a situation where the lighting will never change (and frankly, that is unlikely as even the equipment you use will age and change), then the values you enter will have to be measured for each shot.

if you are this concerned about accurate color, you are just as well off doing the curves adjustments described in my book and including a graycard in every shot. Bruce has some interesting ideas, and this one may have a place, but I am not sure that i would bother with it. balancing for the grays on the card should be enough.

Just got back to the forum.

That is basically what I do. I use a grey card when I think the need arises.