Compare values in RTF template using variables

 Hi,I have a query..
   I have some rows in my rtf template.
col1 - po number
col2 - po value
col3 - item
data
--------
po number    po value       item
---------------     ------------    -------------
12345               100        oil.hsd
23432               110        oil.hsd
23423               123        oil.hsd

now i need to compare the first row value with second row value.. If this is having difference then i need to highlight the second row.
Then i need to compare second with the third and if there is any difference then i need to highlight the third row..


I tried using variables but did not get the result

Any solution !