c#: get the attribute's xpath for an xml element

Given the following XML:

<enrollment>
    <school>
        <students>
            <studentA fname="John" lname="Doe" age="23" />
            <studentB fname="Mary" lname="Johnson" age="22" /> 
        </students>  
    </school>  
</enrollment>

foreach(XmlAttribute attr in node.Attributes)
{
    //--get the XPath for each attribute 
}

Where node = "studentA", how do I get the XPath for each attribute?