Re-grouping XML and grand totals

Hello,

First time trying to do this, so bear with me.

I have a flat xml like:

<G_4>

<PLANT_CODE>

<CUST_NAME>

<CUST_CODE>

<INV_NUMBER>

<INV_VALUE>

<TOTAL_DUE>

<FRM_1_30>

<FRM_31_60>

<OVER_60>

</G_4>

So, this is at the Invoice Number grain. Now, the user wants a summarized view at the CUST_NAME level. So in SQL terms, GROUP BY CUST_NAME and show SUM(TOTAL_DUE), SUM(FRM_1_30) etc.

Reading up the report designers guide, I saw that in an RTF template, I would do :

<?for-each-group:G_4;./CUST_NAME?><?sort:current-group()/CUST_NAME;'ascending';data-type='text'?>

And then for the summary fields do something like: