I've found a concrete reference to Istikapatha in Yasuke Ikari's _A study of the Nilamata: aspects of Hinduism in ancient Kashmir_ (Kyoto, 1994). Ikari also points to Rajatarangini 3.467, where I. is a place where king Ranaditya goes for austerity, said by Stein to be the modern Ramaradan (74:56 long., 34:19 lat.). Nothing on Argalapura, though. D