Embedding docs in Excel

[Les Walker]

I am relatively new to POI and have a requirement to embed attachments to an 
XLS spreadsheet at various locations. From the examples  found I can see how 
the objects get added to POIFS by creating a document node, but I am struggling 
understanding how to connect the rest of this through (it seems) the various 
record entries. Does  anyone have an example of inserting an OLE object into an 
HSSFWorkbook (or POIFS filesystem) in its entirety - or point me to additional 
documentation that would help?