How to set and pass the variable to Watermark setup in Word template

What are the syntax to set and pass to watermark setup in Word template so different page will have different watermark?

<?xdoxslt:set_variable($_XDOCTX,’wMark’, Original)?>

<?xdoxslt:get_variable($_XDOCTX,’wMark’)?>

<?xdoxslt:set_variable($_XDOCTX,’wMark’, 2nd copy)?>

<?xdoxslt:get_variable($_XDOCTX,’wMark’)?>

I got incorrect XPath error

I need to run for 2 setup of the data, should I use watermark or should I setup as Word Art?

Thanks

BIP 11.1.1.9.0 Word 2010