How do I search one excel document, with elements from another document?

Hello Excel forums. I had my first question answered on here, and it was a great experience. So thank you, first and foremost.

Here's my new situation:

I have 2 Excel docs, with A LOT of data in each, one with 9000 rows, and the other with 30000 rows.

I want to take elements from the document "CLEAN UP - accounts - web.xlsx" and search the document "CCSC - web.xlsx" then return the results to a cell in "CLEAN UP - accounts - web.xlsx". So, the elements in column A of the CLEAN UP doc, need to match the number in column B of the CCSC doc, then return the column A element from the CCSC doc, to a cell in the CLEAN UP doc.

I can join the workbooks if need be, so that each page is a worksheet.

Anybody know if I can do something like this with excel, or would i want to use access?