GOOD MORNING: Florence Griffith Joyner, who follows Arnold Schwarzenegger as chairperson of the President’s Council on Physical Fitness, “definitely” plans to continue her fledgling showbiz career. Having appeared in six “Santa Barbara” segs, she’s talking a comedy feature, “The One for a Day” with Morris Day. And also prepping an exercise video … Griffith joined Schwarzenegger last year during his tenure in the Bush administration for “The Great American Workout.” She is now anxiously looking forward to meeting President Clinton — whom she supported in the election … Flo-Jo met Hillary Rodham Clinton and is supportive of her education and health programs. “Education is the key,” Griffith told me. As for her appointment, she said, “I feel honored and very appreciative. I have been in the world of physical fitness for 23 years. I started at the age of 7.” She plans to put emphasis on kids, the handicapped and the elderly. The winner of five Olympic medals, Flo-Jo also works with the Special Olympics. In the ’96 Olympics in Atlanta she plans to run in the marathon — the first sprinter to make that jump … Sunday, President Clinton went on stage at the finale of “The Great Ones” (8 tonight on NBC) to present the Medal of Freedom to Jeanne Ashe, Arthur’s widow … Talking more sports, the overnight numbers of the Chicago Bulls-Phoenix Suns game were spectacular — especially in Chicago, where at one time it rated 60.7 with an 84 share. Even prime time shows that followed on NBC in the Windy City blew the opposition away — f’rinstance “Law & Order” nabbed a 62 share and 44 rating.“A NATIONAL TREASURE,” Don Ohlmeyer’s description of Bob Hope to me yesterday after lunching with Rapid Robert, Linda Hope, NBC’s Warren Littlefield and Rick Ludwin. So, what happens with Hope’s future at NBC? “We’re working out details,” Ohlmeyer said. Hope unspooled fascinating ideas to them and the number of hours will be worked out this week with business affairs. And they are “very close” to the price per hour. “We’re in sync,” Linda also confirmed to me … Euro Disney biz is improving, Frank Wells told me. “The French have finally decided they like it,” said Wells. Added good news for Euro Disney was Sunday’s trial run of the first train through the “Chunnel” (Channel tunnel), signaling next year’s influx of tourists from London to Paris in a half-hour and whisked non-stop via the TGV (Tres Grande Vitesse) train directly into a Euro Disney station … Wells was among guests at the glorious wedding ceremony for Barbara Lee Alexander and David Niven Jr. at their hilltop home. Maid of honor was Barbara’s beautiful teenage daughter, Jessica, and Niven’s brother Jamie was best man. David, in typical Niven whimsical fashion, walked down the aisle carrying the “best dog,” the family’s Jack Russell terrier, appropriately decked out with a flowered collar, trimmed in white tulle with rosettes and bows. It set a typical warm and hilarious note to the wedding. And after the couple recited their vows, 100 white doves flew out from the wedding bower. Joe Moreno’s men musicked and Chasen’s Ronnie Clint and staff presented a perfect “high tea” for the Nivens’ Hollywood friends. To cap the joyous occasion, the guests were treated to a concert by — a marching band of bagpipers. Niven’s dad would have applauded — as did we all. Tony Bill and Helen Bartlett were married June 12 on a hilltop in Antigua, Guatemala. Best “man” was his daughter Francesca and maid of honor, Courtney Valenti. P.S. the wedding party escaped a guerrilla party by one day. WALTER MATTHAU ROLLED up his pant leg, turned up his shirt sleeve, showed me many bruises he received in a fall from — his bike. The last time he took one of these spills was on the eve of the Oscars in 1967 — he showed up with his arm in a sling — but was still able to carry home the Oscar for “The Fortune Cookie” as best supporting actor. This time, he braved the pain (and possible rib fractures) to delight young and adult fans at Saturday’s afternoon preem of “Dennis the Menace” at Mann’s Chinese and the gala bash on the WB back lot that followed. It extended into the night so the kids could enjoy fireworks after the parade of WB cartoon characters, a Sousa Marching Band and other Johnson Entertainment music, Sharon Sacks’ kiddie games and WB commissary’s mammoth outdoor summer fare menu. Joining the WB exex at the feature-from-comics bow was producer Joel Silver — readying movie versions of cartoons “Richie Rich” (Macaulay Culkin to star), “Sergeant Rock” and — ?”My primary audience is the young male genre,” he told me. “I understand them”… It looks set for Oscar nominee Jaye Davidson to join Mario Kassar’s “Stargate,” a futuristic movie, as an alien who is the seed for the planet … Congrats to Carlotta Florio, appointed vice president of special projects at Columbia Pictures … Cedars-Sinai board of governors will hold a benefit Thanksgiving Eve, Nov. 23 at the Shubert — a preview of Andrew Lloyd Webber’s “Sunset Boulevard”… Ann Blyth and husband Dr. Jim McNulty celebrate their 40th wedding anni, Saturday at Lakeside Country Club.