Get Reference to Active Design File C++ V8i SS4

I am wanting to iterate through all the models in my active design file in C++.  Note that I am using V8i.

The "MDL Function Reference" says I need a DgnFileP in order to create this iterator.  Is there a simple way to obtain a pointer to this file object?  

Something like 

DgnModelRefP model = mdlModelRef_getActive();

But for the active design file.

Thank you for your help,