Importing XML with graphic problems

Hi, I am importing an xml document into FrameMaker 11. I have a DTD, template, read/write rules and a XSL stylesheet setup in the structapps file. I am having problems referencing the graphics. My XML is:

<multisheet> <graphic boardno=”FileName”/></multisheet>

What I need is:

<multisheet><graphic boardno=”figures/FileName.cgm”></multisheet>

My XSL is:

<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

<xsl:strip-space elements="*"/>

  <xsl:template match="node()|@*">

        <xsl:copy>

            <xsl:apply-templates select="node()|@*"/>

        </xsl:copy>

    </xsl:template>

   <xsl:template match="multisheet/graphic/@boardno">

        <xsl:attribute name="boardno">

        <xsl:value-of select="concat('figures\', ., '.cgm')"/>

        </xsl:attribute>

    </xsl:template>

</xsl:stylesheet>

My Read/Write rules are:

element "graphic"

{

               is fm graphic element "graphic";

               attribute "boardno" is fm property file;

               attribute "content" is fm attribute "content";

}

  With this setup I am not able to see my diagrams in FrameMaker, any help would be appreciated.