The beta for this problem is quite height dependant really. I'm 6'2'' and when I do it i reach the pinch with my right hand with my right toe on one of the starting handholds, stand up, swap feet and put my right foot way out right on a small edge and then bring my left hand into the faint rib in between the arete and the pinch just as an intermediate hold. Then its just the slightly scary cross into the undercut above the pinch and match to finish!
Hope this helps, as for transformer left hand it sounds like you are doing it right you just have to get your toe or heel to stick, doing that and flipping hte hand is the crux, although the rest isnt easy!
