FileContents & FileGroupDescriptor

Hi:
Is there any document or example about "FileContents" and "FileGroupDescriptor" ?
I have to implement drag a jpg file from my namespace extension to Windows Explorer ,but it doesn't work.
Does anyone have ideas about it,please give me a hand.
Thank you in advance.

Gloria

Were you ever able to find any information on using these two structures? If so, could you please direct me to it?

I am trying to implement dragging attachments from Outlook into my application.

Thanks!