MSXML DOM Special Chars Less Than 32

["Mark Tucker" <MTucker@infoimage.com>]

We are having trouble encoding special characters less than 32 (excluding 9, 10, and 13).  One server is creating an XML DOM and returning the XML as a string.  The calling server is then getting this XML string and loading it into a DOM.  The following VB test app shows that assigning a special character to the Text property doesn't encode it in a way that a later call to loadXML will work:

Dim xmldoc As MSXML2.DOMDocument
Dim xmldoc2 As MSXML2.DOMDocument
Dim strXML As String

For x = 1 To 255
    Set xmldoc = New MSXML2.DOMDocument
    
    Set pi = xmldoc.createProcessingInstruction("xml", " version='1.0'")
    xmldoc.appendChild pi
    
    Set e = xmldoc.createElement("test")
    e.Text = "chr(" & x & ")=" & Chr(x) & ";"
    xmldoc.appendChild e
    
    strXML = CStr(xmldoc.xml)
    
    Set xmldoc2 = New MSXML2.DOMDocument
    xmldoc2.loadXML strXML
    
    If xmldoc2.parseError.errorCode <> 0 Then
        Debug.Print x, "parseError:" & xmldoc2.parseError.reason
    End If
    
    Set xmldoc = Nothing
    Set xmldoc2 = Nothing
Next


The output is:

 1            parseError:An invalid character was found in text content.
 2            parseError:An invalid character was found in text content.
 3            parseError:An invalid character was found in text content.
 4            parseError:An invalid character was found in text content.
 5            parseError:An invalid character was found in text content.
 6            parseError:An invalid character was found in text content.
 7            parseError:An invalid character was found in text content.
 8            parseError:An invalid character was found in text content.
 11           parseError:An invalid character was found in text content.
 12           parseError:An invalid character was found in text content.
 14           parseError:An invalid character was found in text content.
 15           parseError:An invalid character was found in text content.
 16           parseError:An invalid character was found in text content.
 17           parseError:An invalid character was found in text content.
 18           parseError:An invalid character was found in text content.
 19           parseError:An invalid character was found in text content.
 20           parseError:An invalid character was found in text content.
 21           parseError:An invalid character was found in text content.
 22           parseError:An invalid character was found in text content.
 23           parseError:An invalid character was found in text content.
 24           parseError:An invalid character was found in text content.
 25           parseError:An invalid character was found in text content.
 26           parseError:An invalid character was found in text content.
 27           parseError:An invalid character was found in text content.
 28           parseError:An invalid character was found in text content.
 29           parseError:An invalid character was found in text content.
 30           parseError:An invalid character was found in text content.
 31           parseError:An invalid character was found in text content.


I tried playing with the encoding on the initial DOM document, but it has no effect.

How do I properly encode these special characters?  

Mark Tucker
mtucker@infoimage.com