How can we create a variable for running summary?

we have data as below.

seq 1      item no 1001               QTY =50

Seq2      item no 1001                QTY=80

Seq3      item no 1001               QTY =10

We would like to running summary that the results are below.

seq1   ending =50

seq2    ending=130

seq3     ending=140

I create RTF template (word) and created variable and use function

"<?xdoxslt:set_variable($_XDOCTX,'ending',xdoxslt:get_variable($_XDOCTX,'ending')+QTY)?>

<?xdoxslt:get_variable($_XDOCTX,'ending')?>" in variable.

the result in excel is correct when we test ran in RTF template.

But we updated in XML publisher template the result is completed/Warning and the report was shown in XML tag format.