There are a variety of ways to do this, without using different address
books in different batch files. One of my favorite tricks is to redefine
one of the key commands in yarn's config file that runs an external
command. For instance, the X key in Yarn usually gives you a memory with 3
options that decrypts a PGP (Pretty Good Privacy) message and saves it to
a folder, etc. I seldom use this function, so if you want to, you can
define this menu in the config file to overwrite your address book file
with one of three other files. Voila -- you can have up to 4 address
books in yarn, by pressing the X key and choosing a menu option.
Another approach is to use the famous Yes editor for yarn. Yes allows
you to create different files from which you can choose headers or
signatures, based on newsgroup, folder, subject line, or recipient.
Thus, for instance, you should be able to configure yes
start a mail message with the subject line, ``My business contacts'',
up comes a menu of ``To: xxx@yyy'' lines that functions as your address
for business contacts.
A third approach, is to choose an external editor for writing messages,
that is capable of giving you multiple address books, using its macros.
For instance, it is easy to configure virtually any clone of vi to
bring up a variety of addressbooks by pressing one of several keys.
Vim, for instance, will even look up addresses for you in a dictionary
you create, based on the first few letters you give it.