incremental load with update logic

[#1]

Hi Experts,

       i am loading xl files from data folder with incremental logic, i am fetching new files with modified date and time stamp

     and concatenating with qvd .now i have a  change in one of  my xl file which was already loaded in qvd.so i want to load the updated xl

     file in to qvd(Here i dn't have any primary Key). Please help me with some inputs