Bulk ASIN Search

I have 4 excel files with 28,000 lines of part numbers (112,000+) in total, and I need all the numbers matched up with an ASIN number from Amazon. I was using [login to view URL] to do this process, but they can only search in files of 500 rows... So I'm looking for a much more expedited process. Depending on what process you use... I have 4 files with 28,000 rows of data, as well as those same files broken up into 500 rows each if it would help. When matched up, I need the ASIN number and the title of the Amazon listing that it matches to. Let me know if you have any questions, thank you!