Change Field to XML attribute TARGET - PowerCenter

I have a functioning Mapping, which has 4 tables from oracle as source and they are passed on to an XML type target.

This XML file is generated in the following way:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<X_PURCHASEORDERS>
    <X_PURCHASEORDER>
        <X_ADDRESS>
            <XPK_ADDRESS>1</XPK_ADDRESS>
            <TYPE>Shipping</TYPE>
            <NAME>Cristian Osorio</NAME>
            <STREET>123 Mk</STREET>
            <CITY>Buffalo</CITY>
            <STATE>NY</STATE>
            <ZIP>98112</ZIP>
            <COUNTRY>USA</COUNTRY>
        </X_ADDRESS>
        <X_ADDRESS>
            <XPK_ADDRESS>2</XPK_ADDRESS>
            <TYPE>Billing</TYPE>
            <NAME>Ko Lee</NAME>
            <STREET>789 BV</STREET>
            <CITY>Buffalo</CITY>
            <STATE>NY</STATE>
            <ZIP>98112</ZIP>
            <COUNTRY>USA</COUNTRY>
        </X_ADDRESS>
        <X_ITEM>
            <XPK_ITEM>1</XPK_ITEM>
            <PARTNUMBER>897-AA</PARTNUMBER>
            <PRODUCTNAME>DSADSFRSDF</PRODUCTNAME>
            <QUANTITY>1</QUANTITY>
            <USPRICE>125</USPRICE>
            <COMMENTS>A</COMMENTS>
            <SHIPDATE>11-12-2005</SHIPDATE>
        </X_ITEM>
        <X_ITEM>
            <XPK_ITEM>2</XPK_ITEM>
            <PARTNUMBER>897-AE</PARTNUMBER>
            <PRODUCTNAME>OIUOYUI</PRODUCTNAME>
            <QUANTITY>5</QUANTITY>
            <USPRICE>1</USPRICE>
            <COMMENTS>E</COMMENTS>
            <SHIPDATE>11-12-2005</SHIPDATE>
        </X_ITEM>
        <XPK_PURCHASEORDER>1</XPK_PURCHASEORDER>
        <ORDERDATE>1990-10-20</ORDERDATE>
        <PURCHASEORDERNUMBER>99503</PURCHASEORDERNUMBER>
        <DELIVERYNOTES>Comments</DELIVERYNOTES>
    </X_PURCHASEORDER>
 <X_PURCHASEORDERS>

but I need some elements to become attributes.

EXAMPLE

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<X_PURCHASEORDERS>
    <X_PURCHASEORDER>
        ***<X_ADDRESS XPK_ADDRESS="1" TYPE="Shipping">***
            <NAME>Cristian Osorio</NAME>
            <STREET>123 Mk</STREET>
            <CITY>Buffalo</CITY>
            <STATE>NY</STATE>
            <ZIP>98112</ZIP>
            <COUNTRY>USA</COUNTRY>
        </X_ADDRESS>
       </X_PURCHASEORDER>
   </X_PURCHASEORDERS>

Mapping

XML Target