Redline copies of Word - Please advise!!

[Jody]

I work at a law firm where we need to share Word Documents
between another firm but need to protect the changes we've
made to the document so as not to show our legal
strategy. Because I've read that Word documents contain
meta data, we have been scanning the document and sending
it as a .pdf. However, this doesn't allow us to compare
the documents in "redline" style because I can't compare
my latest version of the Word document with the other
firms .pdf version, and vice versa. Ack! Is there any
solution?

Thanks
Jody