[xsl] String contains a regex and then junk ... how to remove the junk?

["Roger L Costello costello@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hi Folks,

I want to convert this:

<REG_EXP>(([\W\w]{1,80})?) &lt;INFO&gt;</REG_EXP>

to this:

<REG_EXP>(([\W\w]{1,80})?)</REG_EXP>

Convert this:

<REG_EXP>([A-Z]{2}[0-9A-Z ]{0,13}) &lt;ARF ID&gt;</REG_EXP>

to this:

<REG_EXP>([A-Z]{2}[0-9A-Z ]{0,13})</REG_EXP>

I want to remove the junk that follows the regex.

I wrote a recursive function to do this. See below. Is there is a simpler way
to do it?

-------------------------------------
<xsl:function name="f:get-regex">
    <xsl:param name="string"/>
    <xsl:choose>
        <xsl:when test="substring($string,1,1) ne '('">
            <xsl:message>Error! Expecting the regex to start with left
paren</xsl:message>
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of
select="concat('(',f:get-regex-helper($string,2,1))"/>
        </xsl:otherwise>
    </xsl:choose>
</xsl:function>

<xsl:function name="f:get-regex-helper">
    <xsl:param name="string"/>
    <xsl:param name="index"/>
    <xsl:param name="count-left-parens-to-match"/>
    <xsl:choose>
        <xsl:when test="$count-left-parens-to-match eq 0">
            <xsl:value-of select="substring($string,1,$index - 1)"/>
        </xsl:when>
        <xsl:when test="substring($string,$index,1) eq ')'">
            <xsl:value-of
select="f:get-regex-helper($string,$index+1,$count-left-parens-to-match -
1)"/>
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of
select="f:get-regex-helper($string,$index+1,$count-left-parens-to-match)"/>
        </xsl:otherwise>
    </xsl:choose>
</xsl:function>