retrieve unique data with duplicate values.

Hello,

I have a list of Serials numbers on column A on sheet 1, with various of data regarding each serials on the following columns (price, items, cost etc.).
On sheet 2 i have a full list of serial numbers with extra data (which is meaningless for this problem). I need to match each serial data on sheet 2 with the data for the same serial on sheet 1.
at first i simply thought of using the VLOOKUP, but I realize I'm having problem with duplicate serials.
I need formula (or even better, Macro) that retrieve data from sheet 1, but if a specific raw on sheet1 already been in use in sheet2, it should go to the next raw with the same serial and collect the data.
I rather VBA because I'm talking about huge list of serials (about 150K) and i can generate the data each time I'm doing changes, and don't need it to be "Live calculations".

I'm using Excel 2007 with Windows 7.
Thanks