[xsl] Document() question

[Kerry Kobashi <kkobashi@xxxxxxxxxxx>]

Suppose I have the following in test.xml:

<?xml version="1.0" encoding="UTF-8"?>
<items>
 <item>
   <refurl="/a/b/c/index.xml"/>
 </item>
</items>

I want to use the document() function to get the refurl and process that 
xml file:

<xsl:variable name="refurl">
 <xsl:value-of select="document('../../test.xml')/items/item/@refurl"/>
</xsl:variable>

Now, I want to process /a/b/c/index.xml:

<xsl:apply-templates select="document($refurl)"/>

I am not able to access the /a/b/c/index.xml file located off my website:
http://www.foobar.com/a/b/c/index.xml

I tried:

document(file:///a/b/c/index.xml)

*Warning*: XSLTProcessor::transformToXml() 
[function.XSLTProcessor-transformToXml 
<http://www.iqlicksoftcms.com/function.XSLTProcessor-transformToXml>]: 
I/O warning : failed to load external entity

document(file://a/b/c/index.xml)

*Warning*: XSLTProcessor::transformToXml() 
[function.XSLTProcessor-transformToXml 
<http://www.iqlicksoftcms.com/function.XSLTProcessor-transformToXml>]: 
remote host file access not supported

document(http://www.foobar.com/a/b/c/index.xml)

*Warning*: XSLTProcessor::transformToXml() 
[function.XSLTProcessor-transformToXml 
<http://www.iqlicksoftcms.com/function.XSLTProcessor-transformToXml>]: 
php_network_getaddresses: getaddrinfo failed:

Any suggestions?

--------------------------
Kerry Kobashi
Kobashi Computing