Creating a binary file

I'd like to create a (proprietary) binary file, on the Windows platform,
using a XSL transformation.  Is this possible?  Are there libraries/COM
Components whatever, that will allow binary output from a style sheet?  
There seem to be a number of applications to convert to XML:fo to PDF.
Does anyone know of something similar (although I'd like it integrated
into the style sheet, if possible) that could help me?
Thx.

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list