Excel lookup latest in list

Hello,

Oh what a challenge this is turning into! In a nutshell i would like to lookup the description of a product in a cell, based on the product code in another. Thats the easy bit and a simple vlookup will do here.

The tricky part is that I want to be able to lookup the last Product code entered.

The sheet looks like this (and i can upload an example when i get to a computer later)...

at b2 there is my "description" cell which is where the lookup will take place.

from b4 to b50 there is a set of cells which are where the product codes will go, and what i want is for cell b2 to look for the cell furthest down that is not blank (ie the last code entered), and then look up the product code to find the description on sheet2, columns a (prod code) and column b (description).