ON A MISSION: Not that long after some of the more hard-core revelers had found their way home following the CFDA Fashion Awards’ after parties, Diane von Furstenberg was already on to the next event by high noon Tuesday. The designer was honored at The Mission Society’s Champions for Children luncheon at the Mandarin Oriental Hotel. Before presenting her with the nonprofit’s Philanthropy Award, André Leon Talley recalled their nights gliding across the banquettes at Studio 54. But Talley was also more tender in describing his friend of more than 30 years. “With all the success and fortune, underneath the veneer of glamour that we both share, there is a little girl who grew up in Belgium and wanted to see the big city lights. She thought with the heart that was always there with the glow and the warmth of the fires built at home,” he said. Dina Merrill Hartley, Stephanie Seymour, Robert Wood Johnson 4th and Bill Ritter were among those in the crowd. Von Furstenberg did what she could to further the cause. She said a visit last week to The Mission Society’s center in Harlem left her most impressed with “how much they care and to see how if you change one child’s life, you change a whole universe’s life. I believe that, because I myself am the daughter of somebody who was supposed to be dead, but she survived and I was born,” referring to her mother surviving more than one concentration camp.