The closest you can come is activating Cirrus Surround with ProLogic II engaged.

It does cause a funky rear soundfield though because the dialog starts leaking into the back surround channels (why CS is pulling stuff from the front channels when used with PL II is beyond me), where in straight PL II mode there is almost zero dialog leakage (at least much better than classic PL).

You aren't really getting any kind of 7.1 processing since the best the Model 950 can do is split mono back channels (6.1). It does not have features like Lexicon's Logic7 or THX Ultra 2 to create a 7.1-like experience from stereo and 5.1 sources.

Dan