[xsl] How to prevent "question mark in block" characters converting xml to csv?

Subject: [xsl] How to prevent "question mark in block" characters converting xml to csv?
From: "KARR, DAVID (ATTSI)" <dk068x@xxxxxxx>
Date: Tue, 2 Mar 2010 10:41:49 -0800
This is partially an Excel question, but I'm writing a stylesheet to
convert an XML file to a CSV, and I have to do some things to make it a
valid CSV, like quoting the values, escaping quotes, etcetera.  One
thing that I don't see how to solve is that if the resulting CSV field
has embedded newlines, when I view the result in Excel, the end of each
embedded line has a "question mark in block" character.  How do I have
to massage the transformed xml data to prevent that?

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