Here4s the full case test:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
	<xsl:template name="replace-values">
		<xsl:param name="textfrom"/>
		<xsl:param name="textwhere"/>
		<!--xsl:variable name="textfrom" select="concat($textfrom0,'&amp;')"/-->
		<xsl:variable name="lower">abcdefghijklmnopqrstuvwxyz</xsl:variable>
		<xsl:variable name="upper">ABCDEFGHIJKLMNOPQRSTUVWXYZ</xsl:variable>
		<xsl:choose>
			<xsl:when test="contains($textfrom, '{')">
				<xsl:variable name="lookfor"
select="substring-before(substring-after($textfrom,'{'),'}')"/>
				<xsl:variable name="before" select="substring-before($textfrom,
concat('{',$lookfor,'}'))"/>
				<xsl:variable name="after" select="substring-after($textfrom,
concat('{',$lookfor,'}'))"/>
				<xsl:variable name="value">
					<xsl:variable name="ulookfor" select="translate($lookfor, $lower,
$upper)"/>
					<xsl:variable name="llookfor" select="translate($lookfor, $upper,
$lower)"/>
					<xsl:variable name="utextwhere" select="translate($textwhere,
$lower, $upper)"/>
					<xsl:variable name="ltextwhere" select="translate($textwhere,
$upper, $lower)"/>
					<xsl:choose>
						<xsl:when
test="substring-before(substring-after($utextwhere,concat($ulookfor,'=')),'&a
mp;')">
							<xsl:value-of
select="substring-before(substring-after($utextwhere,
concat($ulookfor,'=')),'&amp;')"/>
						</xsl:when>
						<xsl:when
test="substring-before(substring-after($ltextwhere,concat($llookfor,'=')),'&a
mp;')">
							<xsl:value-of
select="substring-before(substring-after($ltextwhere,
concat($llookfor,'=')),'&amp;')"/>
						</xsl:when>
						<xsl:when test="substring-after($utextwhere, concat($ulookfor,'='))">
							<xsl:variable name="stest" select="substring-after($utextwhere,
concat($ulookfor,'='))"/>
							<xsl:if test="not(starts-with($stest,'&amp;'))">
								<xsl:value-of select="substring-after($utextwhere,
concat($ulookfor,'='))"/>
							</xsl:if>
						</xsl:when>
						<xsl:when test="substring-after($ltextwhere, concat($llookfor,'='))">
							<xsl:variable name="stest" select="substring-after($ltextwhere,
concat($llookfor,'='))"/>
							<xsl:if test="not(starts-with($stest,'&amp;'))">
								<xsl:value-of select="substring-after($ltextwhere,
concat($llookfor,'='))"/>
							</xsl:if>
						</xsl:when>
					</xsl:choose>
				</xsl:variable>
				<xsl:value-of select="$before"/>
				<xsl:value-of select="$value"/>
				<xsl:call-template name="replace-values">
					<xsl:with-param name="textfrom" select="$after"/>
					<xsl:with-param name="textwhere" select="$textwhere"/>
				</xsl:call-template>
			</xsl:when>
			<xsl:otherwise>
				<xsl:value-of select="$textfrom"/>
			</xsl:otherwise>
		</xsl:choose>
	</xsl:template>


	<xsl:template match="/">
		<xsl:call-template name="replace-values">
			<xsl:with-param name="textfrom"
					select="'list_entidadeprocessos.aspx?k=PAI&amp;entidade_k={ENTIDADE_K}&a
mp;processo_k={PROCESSO_K}'"/>
			<xsl:with-param name="textwhere"
select="'?businessclass=PROCESSO&amp;ENTIDADE_K=&amp;processo_k=xx0001'"/>
		</xsl:call-template>
	</xsl:template>
</xsl:stylesheet>