How many times have man utd and Barcelona met in the champions league?

The first thing that struck me immediately when reading this text, is that your grammar is simply preposterous. The question should have read, How many times have Manchester United FC beaten Barcelona FC? To answer your question Manchester United have beaten them only once when Barcelona scored 6 own goals in one half. However the match was abandoned because a dog ran onto the pitch and bit the referee, unfortunately the dog had rabies, and this turned the referee into superhero, much like what happened in Spiderman. Manchester united appealed against the game being abandoned but this was overturned by the FA because the dog was owned by Alex Ferguson.