After much digging about, it would seem that I am getting a little bit closer to a solution.

It seems that there are some people over at the GNOME project writing a C library to handle OLE structured storage. The library is called libole2.

Since Perl and C get on so well together, it would seem that I might be able to do it after all, with much less work than I originally thought. I will keep posting as I get further into it.

Anton