[quote user="Jon Summers"]The short answer is: you can't.[/quote]
Well ... I have not tested it, but what I remember from some discussions I found on Internet, there are some workarounds possible. But I agree it's not possible using standard COM Automation tools. And what I remember also, the workarounds were not very straighforward and was usually based on Win32 API, so I assume there are not general and cannot be used in all situations.
With regards,
Jan