Insert 1 result if a cell contains one of several possibilities

Hi All,

I am new to this level of excel - but what I need is a formula that does the following :

Insert <result a> if an adjacent cell contains one of up to 30 possible text strings (2 specific initial letters from a string of 7 or 8 characters) , but <result b> if it contains one of 30 other different possibilities - and so on - up to 4 different results - generated by 4 different groups of about 120 possibilities

Actual example based on UK Postcodes -

AB ------> Salesperson 1
AL ------> Salesperson 2
B --------> Salesperson 3
BA ------> Salesperson 4
etc

Salesperson A covers approx 30 possible Postcodes
Salesperson B covers 30 different possible Postcodes.. and so on...

I would really appreciate any / all help received..

Thank you in advance

Dan...