Formula to tag list of Items with Grouping Number

I have a list of items that are all coded (1500 or more items)
eg BEBSHD6 , FOAT122 , HWTD5 etc
The first two letters of each code denotes what catagory or group the item belongs to
I have another list which has the two letter codes of all the 34 different item groups
eg BE , FO , HW etc
In the column next to these two letter codes is a number (1 to 35)
eg BE next to 24 FO next to 1 HW next to 12 etc

I am trying to create a formula in excel that will look at the first two letters of the item codes
Then find these first two letters in the other list (the two letter groups list)
Then tell me what the number is next to that two letter code

This number has to be displayed next to the item code on the first list

I Have tried lookup using LOOKUP(LEFT(A2,2) etc jsut can't get it to work
I tried LOOKUP(LEFT(A2,2) and then if it equals the two letter code show me the number next to it
But it only works for seven looks (my beginner terminology)

Any genius out there can you please help

Thanks
Rob