Does lxml supports xslt functions (http://www.w3schools.com/xpath/xpath_functions.asp)

I have the following xsl file

<xsl:template match="PropertyIsLike">

<xsl:variable name="literal" select="//Literal"/>

<xsl:variable name="wildcard" select="//Literal[@wildCard]"/>

<Statement><xsl:value-of select="//ValueReference" /> LIKE '<xsl:value-of select="fn:replace($literal, $wildcard, '%')" />'</Statement>

</xsl:template>

and try to replace some characters in the //Literal tag of the xml file

xml file looks like the following

<Filter><PropertyIsLike wildCard="*" singleChar="?" escapeChar="!"><ValueReference>highway</ValueReference><Literal>bus?st*</Literal></PropertyIsLike></Filter>

Any hint, ideas, ... welcome.

Thans a lot in advance