I think I get the idea, though I admit the last time I took statistics was . . . a long time ago.
Either way, what I'd try doing is going into the Expected PP Hit Flop stat and on the Format tab of the stat editor, you can edit the summary expression there. I believe if you explicitly put something to the effect of "2 * 0.322 * cnt_holecard_sqrt" there it should do what you want. I honestly haven't spent too much time working with the summary expressions, though, so you may have to fiddle to get it exactly right? Either way, do keep us posted and let us know if you get it working.