I've been following this thread, with interest, because I'd had the same initial problem with FH3 and eventually chose to adopt the Chapman Codes to pinpoint places I wanted to record. This was for several reasons :-
1. The number of columns available in FH (as identified by GeoffWalter),
2. The fact that the vast majority of events I need to record are within the UK (ie covered by the Chapman Codes),
3. The majority of BMD events are identified within Registration Districts and the excellent coverage of these at
http://www.ukbmd.org.uk/genuki/REG/districts/index.html,
4. I realised that IF I used the Chapman Code to identify the County, then the Country was already identified and, thus, I would not need a 4th column.
5. As identified by Chris, many places changed Registration District, County or Country over time But if the Registration District where the event was recorded is used then the Chapman Code can be found in Genuki.
However, I've just found an alternative. The Genuki website has a note which says that the Chapman Codes have been updated and included in an International Standard ISO 3166-2:GB and details are on Wikipedia. In simple terms, the ISO-3166 standard uses a 2 character code for each country/Territory followed by another code to indicate their sub-division.
There is a very good explanation of ISO-3166 @
http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 which has a grid showing the codes being used and {at the bottom of the page} a link table to other pages which identify sub-divisions of Countries.
So - the Chapman Code for Hampshire is HAM and that is what I've used for most of my family. The ISO3166 code is GB-HAM unless it's in the Southampton area which is GB-STH or Portsmouth GB-POR. The major advantage here is that, obviously, only one column is required to record both the County and the Country.
I'm sticking with the Chapman Codes until I find lots of relatives who emigrated!
Hope this helps
Bilko