How to add new areas to a model

I have a structured mesh model already developed and I need to add a neighboring area to that model. Is that possible? If so, How it is done, can you guide me to documentation that explains how it is done?
Hopping you can answer, Emília Novo

There's currently no way to directly add to the model. You can create an additional mesh for the neighboring area (making sure that at the common border with the existing mesh the nodes are identical), and then import both meshes (2D) into one (for example, from shapefiles). All the model setup, however, you have to repeat from there.