What is the best way to handle the case where you would end up with too many references in a digital signature?

If I have an XML Document, where I need to sign say up to two hundred
different elements (different parts of a very complex form for example),
I think I will end up with up to 200 references, in the SignedInfo or
manifest, whereever we decide to put them.
We did think about using an XPath expression, but that would get too
large and performance might be an issue I think.
 
What is a good way to handle such a scenario?
 
Thanks,
 
-- Sanjay