I'm sorry, I had the story all wrong. This is the scenario.
I have 2 separate workbooks of data. The "new" one has 1000 rows of data. The "old" one has 750 rows of data. They both have the same exact columns. I need to look at the data in column "C" which is a unique part number. I have to find which 250 records have been added to the “new” and add them to the “old.” So, 250 records will be added to the "old" one and 750 records remain.
Your help is greatly appreciated, Karen