Need help! Macros to compare worksheets preferably workbooks

I am looking to create a macros in excel. I have data that I need to compare in the entire workbook starting at A4:Z4 there is no set end when it comes to data in the columns could stop at 10 could be in the 1000s. I need something that will compare and remove any duplicates in a worksheet. I prefer that it just leaves the field blank as to not mess up the numbers of excel. Lets say workbookA is the original and workbookB is the newest one. I would like to be able to compare the two and if something isnt on WorkbookB but was on workbookA, I'd like that to be cleared out. This is for a report that I get every quarter that right now I have to manually go through and it took me 20+ days this month. There has to be a less time consuming way to do this. Can someone please HELP!!!