Using XPath to refer to a tag value which itself is XM

Hi,
I have a XML file content which is added as the value of XML tag.

For eg:
In this xml snippet, value of tag <RawData> is xml content itself.

<root>
<OID>27696.16415.10544.53961</OID>
<Rawdata>
<report><primaryImages><primaryImage><ObjectName>auto_21259132174955</ObjectN
ame></primaryImage></primaryImages></report>
</Rawdata>
</root>

Now, if I use XPath to navigate through this XML content, it does not display
anything.
...
   <xsl:value-of
select="Rawdata/report/primaryImages/primaryImage/ObjectName"/>
...

But, if I use below XPath, it gives the entire XML content.
...
   <xsl:value-of select="Rawdata"/>
...

How should I add such value so that Xpath can consider it as XML?

Thanks
arvind