Large Excel spreadsheet...SLOW

Question

Hello all,

I have a worksheet that has over 8000 lines w/ 7 columns of information, 2 of those being bar code numbers that I need to work with.  Each day I need to take 3 excel reports of scanned bar codes and match them to the main list with each of those 3 matching one or both of the bar code columns. Conditional Formatting allows me to mark each uniquely, but of course slows down my spreadsheet to a snails pace when I need to sort what has and hasn't been scanned. I've never used VBA or Pivot Tables and would love to learn all the nifty things excel can do, but most of what I am finding online is pure "greek to me".  Any help would be appreciated, unfortunately I cannot share all the data on the worksheet.

Thank you, S_E