Using EXEC_REST_WS to call an Outgoing REST Web Service with XML

Hi,

I am trying to call an outgoing REST web service using EXEC_REST_WS and need to POST XML data to the web service.  Does anyone have any insight how to do this please?

I have defined the Name, Base URL, etc of the outgoing REST web service in Administration / Web Services / REST Web Services and have set the Content Type to XML.

However, when I call EXEC_REST_WS it seems to insist that I pass JSON input.  I cannot see how to pass XML input. 

Here's an example of the XML I am trying to send:

<Criteria limit = "7" query = "PART" match-type = "EXACT" ompn = "1">
<Criterion id = "CustomPartID">
<Parameter name = "PARTNO" match-type = "EXACT">MYPARTNO</Parameter>
</Criterion>
</Criteria>

The code I have at the moment is:

Local Char PCOD(100)(1..10),PVAL(100)(1..10),HCOD(100)(1..10),HVAL(100)(1..10)
Local Clbfile CDATA(0), RESHEAD(0),RESBODY(0)

CDATA   = '<Criteria limit = "7" query = "PART" match-type = "EXACT" ompn = "1">'
CDATA += '<Criterion id = "CustomPartID"><Parameter name = "PARTNO" match-type = "EXACT">MYPARTNO</Parameter>'
CDATA += '</Criterion></Criteria>'

# Call the web service
RETVAL = func ASYRRESTCLI.EXEC_REST_WS(
&        "TPPXMLAPI","POST","/xmlsearch_test.asp",PCOD,PVAL,HCOD,HVAL,CDATA, 0, "",RESHEAD, RESBODY)

When I run this code, I get an error: "Unexpected token < in JSON at position 105"