Access columns in Non-Standard SQL

Hello,

I am calling a SQL Server stored procedure as my datasource using the "Non-Standard SQL" option.

This produces an XML dataset as follows:

<?xml version="1.0" encoding="UTF-8"?>
<!--Generated by Oracle BI Publisher 11.1.1.7.141014 -Dataengine, datamodel:_so_dk_TEST_AbaSec_Test_Abasec_ScheduleTrigger_Test_xdm -->
<ROWSET>
  <G_1>
  <recordtype>H</recordtype>
  <clientplaceofbooking>FRA</clientplaceofbooking>
  <creditdebitcode>D</creditdebitcode>
  <tottaxamount>28,12</tottaxamount>
  </G_1>
</ROWSET>

However, on the BI Publisher screen I see it as a global level function as in the screenshot below. I would like to access the column variables in my AfterData trigger. Is there any way of achieving this?