And who said things go better with Coke (or Diet Coke, for that matter)? Apparently not Daryl Hannah, who demanded that Coca-Cola Inc. stop using a clip from the Columbia film "Roxanne" (in which Hannah co-stars with Steve Martin) to promote Diet Coke. Julie Richard, a spokeswoman for the actress, said Monday that Hannah had asked Coca-Cola Inc. to stop using the clip a week after "Roxanne's" June 19 opening and that lawsuits had been discussed at that time. But Richard said Hannah was satisfied that Columbia (which is owned by Coca-Cola Inc.) formally apologized Monday. A statement issued by the studio said it understood Hannah "has a strict personal policy not to endorse . . . any commercial product." Columbia added that the commercial "was conceived strictly as a promotional tie-in and was at no time intended to be a commercial endorsement."