Which one may more officially works? To represent company "in front of" community, "before" community, or "dealing with" community.
One can represent a company "for" a community if one is describing the scope of one's representation - e.g. for specific regions or specific accounts. This would sound pompous if said to the community.
As a representative, once can "work with" or "deal with" specific clients, regions, cities, etc. Maybe "in matters relating to [company]". This would sound better when introducing myself to the community
"before" sounds pretentious, like a courtroom
"in front of" sounds odd. I cannot figure out a place where I would use that