Hey everybody, my name is John. I commonly refer to these forums for many issues I have with Excel and you guys seem to always come through. However I think I have met my match with this issue and was wondering if you might be able to help me out...

I have a list of part numbers for automobiles that is updated every month. There are about 400,000 part numbers in the sheets. I am creating an online store to sell these parts but I need to update the store every month. Each month the manufacturer adds about 3,000 part numbers. We'll say those part numbers are in column A.

In column B there are notes regarding any changes that are being made that month to the part numbers in column A. These changes include codes that tell if the part is being discontinued or superseded (changed) to a different part number.

What I need to do is first evaluate column A and figure out which part numbers were added (or removed - although the removed part numbers would have had the discontinued code next to them the previous month). I also need to compare each of column A's respective column B to ensure that that specific part number is not being discontinued or changed that month...

I really don't know where to start on this... Any recommendations or insight you can offer would be greatly appreciated! Thank you for your time.

-John