LAS VEGAS — The spirit of Celine Dion hovered over CinemaCon, if only because the Canadian songstress let the convention borrow her venue for the week.And comedians both amateur and professional got plenty of mileage out of it — Jack Black burst into a verse of “My Heart Will Go On” while onstage to pimp “Kung Fu Panda 2,” and so did Hugh Jackman before presenting “Real Steel.” But CinemaCon managing director Mitch Neuhauser discovered the hard way that conventioneers take their Celine seriously. Moments before the Disney presentation March 29, he hinted that she was at the Colosseum and would come out to perform. The loud cheers turned to jeers when he admitted he was only joking. In one of the most ambitious presentations ever at the conference, Sony converted the Colosseum entryway into a real zoo with lions, bears and a monkey named Ripley on March 30, themed for the studio’s screening of Kevin James comedy “Zookeeper.” And during what likely will become one of the confab’s more talked-about moments, Sony distribution exec Rory Bruer walked onstage carring a baby bear, which promptly peed on him. “Thanks for sharing,” Bruer quipped. Prior to Bruer’s memorable shower, Cameron Diaz received the confab’s Female Star of the Year award. Diaz, who stars in Sony’s upcoming “Bad Teacher,” was given the award by friend Drew Barrymore. “Thank you Poo Poo,” Diaz said as Barrymore presented her with the kudo.