Firstly, you need to form some sort of group committee made up from the Objectors........and elect a chair-person.
Secondly, the chair-person needs to make an appointment with the Planning Department and discuss 'exactly' why the original application was refused. They should ask for copies of all relevant information, i.e. Sections of the Local Plan, under which the application was declined...and all relevant legislation, etc.
It is true that many Planning Departments simply do not have the funds to fight protracted appeals, but the Pressure-groups willingness to act as the Councils 'legs' can reduce the financial impact; especially if they only have the chair-person to deal with rather than be swamped with a large volume of correspondence/'phonecalls from concerned villagers.
Once you have details of the legal footing upon which the Refusal was based, you need to find out on what grounds the Appeal is based.
You may wish to consider engaging a Planning Consultant, these are often people who have had experience working in LA Planning Departments.