Do you mean is import 3D model?.
Simply click file/import 3D model and will find grand ma 3D - import windows, click import 3d model On the next save icon on gma3d - import window. And locate the file do you want to import, must 3ds files.
You can scale the object or 3dmodel, 1 milimeter on foreign application is 1 meter on grandma 3d.