Find out what style of dancing is typically danced at those mixers and take some classes in that style. I'm sure you can find something in your local dance studios or maybe some evening classes in community colleges - usually you don't have to enroll...
That's a tough one - but it sounds like it was Woody Allen so I cheated and did a web search and believe it or not it is Woody Allen - sometimes I am pretty good - lol. Good Luck!!!
Allen and his killer crossovers could smoke Allen's slow as$ any day.