Embed an existing graph in an existing graph

So I know how to embed a new graph inside of an existing graph. You just open the tools and then right click on the graph and create a new graph inside. But I would like to take a graph that I have already created (with many curve fits and such applied) and embed it into another graph as an inset. I could remake the graph, but it seems like there should be an easier way to do this.

What is probably most useful to you is:
#include <InsertSubwindowInGraph>

This can be located from the Help Browser -> Wavemetrics Procedures -> WM Procedures By Topic -> [Graphing]
This will add an item at the bottom of the Graph Menu.