Need to find element name of corresponding attribute

I need help finding a method for getting the name of an element based on the corresponding ID and IDREF attributes. I cannot use the id() function because the project I'm working is converting well-formed XML to DTD compliant XML. The id() function doesn't work because there is no DTD that defines ANY attribute types. So basically assume the ID attribute is defined as CDATA and not ID.

Here is basically what I'm working from:

<service id="M202-01">
<title>TITLE</title>
<para>See <xref taskid="M202-02"/>.</para>
<para>Stuff</para>
</service>
<remove id="M202-02">
<title>TITLE</title>
<para>Para stuff</para>
</remove>

I need to identify the name of the element that contains the ID value of the the "taskid" in <xref>. Once I have that, I can grab the value of the child <title> element.

C. Flanders