How about opening a popup window?
var popup=window.open("","")
popup.document.write("<pre><![CDATA["0
popup.document.write(objDOM.xml.toString())
popup.document.write("]]></pre>")
popup.document.close()
The browser may not like the <![CDATA[...]]> tags. If it doesn't, try <xmp>...</xmp>.
Another option is a textarea.
var popup = window.open("","")
popup.document.write("<html><head><title></title></head>")
popup.document.write("<body><form><textarea cols='60' rows='30'>")
popup.document.write(objDOM.xml.toString())
popup.document.write("</textarea></form></body></html>")
popup.document.close()
Finally, you could use a textarea directly in your master page.
document.forms.formName.textAreaName.value = objDOM.xml.toString()
HTH