It's for the planning and zoning board to fight this, since it is their decision being appealled--you want to push the board to defend their decision and support them in doing so.The board defends its decision by refuting the arguments for its overturning, showing that the decision was well-considered and complied with all procedural rules, and providing legal "authority" or "precedent" (e.g. cases) supporting the board's discretion and their decision should be upheld. The board must hire a lawyer to represent it (or if any board members are attorneys, they can present the board)--the lawyer(s) should know how to do this (if they don't, hire other lawyers).