unicode numeric character references in xml output

Hello,

I'm transforming XML to XML, and I need to pass
through the unicode numeric character references (hex)
from the source to the output. That is, I need
"’" in the input to appear as "’" in the
output. I'm using XSLT 2.0 and the Saxon 9B processor.

Unfortunately, the set of possible character
references is large. (The transform works on a very
large set of scientific articles. These may include
special characters in author names, article titles,
etc.) I originally looked to character maps as the
solution, but I don't see how to map the entire
unicode set.

Thanks,
Andrea