Get mesh of instanced GeomObject

[Anonymous]

How can I get the mesh from an instanced GeomObject?

In maxscript I do:

gsphere = createInstance geosphere radius:1 segs:4
gsphere_mesh = gsphere.mesh

Here is the first line of the maxscript translated into C++:

GeomObject *GSphere = (GeomObject*)ip->CreateInstance(GEOMOBJECT_CLASS_ID, GSPHERE_CLASS_ID);
GSphere->GetParamBlockByID(2)->SetValue(0, 0, 1);
GSphere->GetParamBlockByID(2)->SetValue(1, 0, 4);

Now, I need to get the mesh, but I cannot figure out how.  There is no "GetMesh()" or "GetTriMesh()" functions.

Thanks for any help.