Fashion icon Valentino hosted a private reception in honor of Joan Collins at the Loews Regency the other night to toast her one-woman show, which ends Saturday at Feinstein’s at the Regency. A source said, “It was an intimate midnight reception with Joan and her husband, Percy, to toast her success.” Those who’ve packed in to see her show include Clive Davis, Nikki Haskell, Neil Sedaka, Michael Kors, Mario Testino, Alan Cumming, Barbara Taylor Bradford, Regis and Joy Philbin, and Michael Feinstein himself.