I am trying to make some global changes to the telephone number fields in my
Outlook/Exchange address book (most of them are in the wrong format). I am
thinking the best way to do this will be to export the address book in an
appropriate format (probably Excel) then use the replace/change function to
make the changes required. I could then import the file back into Outlook.

My question is whether I need to export every field that I know I have used
in any of my contacts or whether I could just export, say, Name, Home Phone,
Business Phone and Mobile Phone and whether when I re-the import just those
fields they will update only those fields in the address book leaving the
others untouched. If not I would end up with address book that only has Name
and the various phone numbers. If I'd DO need to export all of the fields, is
there a way I can do this?