Need Alot of Help with VBA, Comparing 1,000+ Excel Files for Duplicate Serial Numbers.

Greetings,
I Have over 1000+ Excel Worksheets and csv Files sitting in FolderA, I need to search these files for any duplicates in Serial numbers located in my Master Worksheet B. I need help creating a Macro to Search all the files in FolderA and compare them to my Master WorksheetB. If any serial numbers match I need to import the File name into column B of my master Spreadsheet. I've been working this for weeks without solving this issue, now I'm trying to self teach VBA.

I'm using Excel 2010, and most the files are structured the same.

So basically if any of the serial numbers listed in Column P of of the 1000+ Excel files in FolderA match a serial number in Column A of my Master WorksheetB, I want to import the name of that file into ColumnB next to the serial number it matched.




I really appreciate any help

An easier Macro
If anyone knows how to make a Macro to Import a column from a large quantity of files to a new worksheet that will work too.
The Macro should do something along the lines of
-Open every Excel worksheet in FolderA
-Copy the Serial numbers in Column P from each File
-Paste Serial Numbers in column A of a newWorksheet and the File name it came From in Column B

If someone could help me get this far I may be able to do the rest.
Thanks.