To attach file to a workbook in a addin.

[Subodh]

I want to attach a file to the workbook or an addin.
The file may be a picture file that is some special logo that is part
of the excel
or some other dll file needed to run the addin
Like we insert the new form from one workbook to another
is it possible to insert files on non excel type. *.jpg,*.gif,*.dll or
some other
Any tips will be appreciated.