Conditional test question

I have this working pretty well, but was wondering if there is a better way 
to do this?

In both cases <sectionNumber> and <tagName>, I am testing the 1st 4

characters for some value (GC1_, GC2_, GC3_ etc) and am changing the value 
based on this.

In <SectionNumber> it is going to be either a 0,1,2 or 3.  In TagName, I
am 
changing the 1st 4 characters to either GS_ or GR_.  I just doing a bunch of 
"when" statements and was wondering if there is a better way to do
it.

Also, another possibility was to test the 1st 2 characters as well as the 
4th character for an "_". Would I do it like:

<xsl:when test="substring(name(),1,2) = 'GC' & substring(name(),4,1)
= 
'_'"/>

Here is the current code.

 <xsl:template match="FIELDS/*">
  <form>
   <sectionNumber>
    <xsl:choose>
     <xsl:when test="substring(name(),1,4) = 'GC1_'">
      <xsl:text>1</xsl:text>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'GC2_'">
      <xsl:text>2</xsl:text>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'GC3_'">
      <xsl:text>3</xsl:text>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'RC1_'">
      <xsl:text>1</xsl:text>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'RC2_'">
      <xsl:text>2</xsl:text>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'RC3_'">
      <xsl:text>3</xsl:text>
     </xsl:when>
     <xsl:otherwise>
      <xsl:text>0</xsl:text>
     </xsl:otherwise>
    </xsl:choose>
   </sectionNumber>
   <primary>True</primary>
   <formName>
    <xsl:value-of select="../../@FORMCODE"/>
   </formName>
   <tagName>
    <xsl:choose>
     <xsl:when test="substring(name(),1,4) = 'GSU_'">
      <xsl:text>GS</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'GC1_'">
      <xsl:text>GS</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'GC2_'">
      <xsl:text>GS</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'GC3_'">
      <xsl:text>GS</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'RC1_'">
      <xsl:text>GR</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'RC2_'">
      <xsl:text>GR</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:when test="substring(name(),1,4) = 'RC3_'">
      <xsl:text>GR</xsl:text>
      <xsl:value-of select="substring(name(),4)"/>
     </xsl:when>
     <xsl:otherwise>
      <xsl:value-of select="name()"/>
     </xsl:otherwise>
    </xsl:choose>
   </tagName>
   <flags>0</flags>
   <format>0</format>
   <value>
    <xsl:value-of select="."/>
   </value>
  </form>

Thanks,

Tom