DCR value to be compatible with XMLoutput

System

I try to use TeamSite Templating to edit/update a XML file, not a HTML file. This idea is to let the presentation-level will be maintained in the XSLT file.
The WEB application will take this XML (generated/deployed by TeamSite Templating/OpenDeploy) and XSLT to be the output to the end-user.

So, I have created a presentation template tpl file with XML-format, so, I used many CDATA tags for displaying XML tag name,
and using iw_iterate, iw_value tags to get the data from DCR.

But I found that although the real text data in the DCR file is using '&amp;' and '&lt;' to represent '&' and '<',
as long as I use iw_value to get value from DCR, The values always be '&' and '<', these two character will be invalid in the output XML.
After I choose 'generate' function in DCR Editing window, the output XML will contain these invalid characters: '&' and '<'.
Does anyone have idea how to real-time transform these two characters: '&' and '<' to '&amp;' and '&lt;' in presentation template file?
Thanks a lot.

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I am a newer in using Interwoven Products