Populate column for list of towns

Hello Guys
I am new and have just registered, I have been trying to solve a problem for over a week now in excel.

I have a list of towns, region

The list is over 1500 records for each

I was wondering if there is a way I can fill in the region and country columns automatically -i.e. through a script or function or macro based on what is entered in the town row/ field

e.g

Town= Cheltenham

if the town is Cheltenham, I would like the corresponding region column to pollute with glouctershire

I have tried using functions such as:

=IF(A3="CHELTENHAM","Glouctershire",IF(A3="LONDON","LONDON",IF(A3="Leeds","Yorkshire",A9)))


but as I have over 1500 towns, the error message comes up in excel stating the formula is too long- I think it is limited to 255 characters or so

I would appreciate any help as it is urgent.

Thanks to all in advance[/SIZE][/SIZE]