sys_CheckBoxTree getting labels from values

Hi I have got as far as using a lookup to pass a checkbox value id and return the label
$rx.doc.extractBody($rx.doc.getDocument("…/lookups/country_name_lookup.xml?country=$country"))

However this returns an xml file and I want to extract the lable string. Is there a function for doing this?

OK I think what I need to do is write a simple xsl to output just the values