Merge data in Excel 2k without pasting

Hi Pals,
greetings and salutations! Recently I was asked by two users who were working on the same workbook(not shared)that they wanted to put their data together, and I did it manually. But look at this scenario, there are two pple working on exactly the same workbook, but saved differently. Let?s say each of them is entering data in particular rows in their respective copy of the workbook. Now we want to copy the data from person 1?s workbook to person 2?s workbook, without overwriting. How can I do this without the laborious copy-and-paste routine, just in case the rows were far apart and randomlydistributed?