Hi guys,

I am a novice to marco/vba and am hoping to get some guidance on extracing unique values based on two lists(2 sheets).

My scenario:
  • Sheet1 has one million lines of serial numbers (master sheet)
  • Sheet2 has 200,000 lines with same format. ColumnA=serial
  • sheet 2 has some new serials and some existing serials
  • Serial is 18 digit number saved as text (dunno of that matters)


Solution?
  • how can I get vba to check serial agaisnt serial ( Sheet2 ColumnA against Sheet1 column A)
  • extract all new serials (unique of sheet 2 only)
  • unique lines to export to new sheet or replace sheet2


I am really unsure how to start this... any ideas or pointers?

I've googled my heart out for a week but haven't found anything that works.. I've found formulas& excel functions but they keep crashing my comp because of large data in sheet 1.

Thanks in advance for any advice and your time!