Other than native excel library and CSV, look like we can just use tab (\t) to separate the columns: http://www.devx.com/Java/Article/31356/1954?pf=true

check cell value exist in another column - http://stackoverflow.com/questions/12915215/excel-check-if-cell-value-exists-in-column-and-then-get-the-value-of-the-next http://stackoverflow.com/questions/11315551/find-if-value-in-column-a-contains-value-from-column-b

Remove duplication from Excel - https://www.freecodecamp.org/news/how-to-remove-duplicates-in-excel-delete-duplicate-rows-tutorial/