applying templates to attribute value

Hi guys,

Not exactly a newbie anymore, after reading these posts for a while I have learned quite a lot, but I have what I feal might have a nagging beginner problem that I have not been able to deal with.
Perhaps it has no solution in XSL, but even knowing that would help.

Here is the problem in a nutshell, how can I applying a template to string content in an attributes value. My specific digital asset management application has HTML formatting in an attribute value that I have to transform into fo formating. I have the formatting templates, but I cannot seem to match them to the attribute value. Can anyone give me a quick hand?

Thanks in advance.


XML: ==================================

<TEAMS_ASSET_FILE>
   <METADATA>
      <UOIS>
         <GT_ASSET_REQUEST_MD COVERLETTER_TEXT="This is a &lt;b&gt;test&lt;/b&gt; of the line break formatting&lt;br /&gt;. Did it work?" />
      </UOIS>
    </METADATA>
</TEAMS_ASSET_FILE>

XSL: ==================================

<xsl:template match="TEAMS_ASSET_FILE">
   <xsl:apply-templates select="./METADATA/UOIS/GT_ASSET_REQUEST_MD/@COVERLETTER_TEXT" />
</xsl:template>

<!-- formatting in the block -->
<xsl:template match="//GT_ASSET_REQUEST_MD/@COVERLETTER_TEXT">
  <xsl:apply-templates />
</xsl:template>
<xsl:template match="br">
  <fo:block> </fo:block>
</xsl:template>
<xsl:template match="b">
  <fo:inline font-weight="bold">
    <xsl:apply-templates select="*|text()"/>
  </fo:inline>
</xsl:template>

</xsl:stylesheet>