I want to set up a setting that does not transfer only certain directories.

RewriteEngine on
RewriteCon%{HTTP_HOST}^abcd\.sakura\.ne\.jp(:80)?$
RewriteCond%{REQUEST_FILENAME}!^/shoki2/wp-admin/
RewriteRule^(.*)$http://example.com/$1 [R=301,L]

That would be fine.

It may have already been resolved, but if you want to permanently transfer to a new domain (proprietary domain) and only "do not transfer" a specific directory, why not place .htaccess in the document root (/) with the following rules?
(It's almost the same as @suzukis...)

RewriteEngine On
RewriteBase/
RewriteCond%{REQUEST_URI}!(^/shoki2/wp-admin/)
RewriteRule^$ http://example.com/ [R=301,L]

Also, once you finish the rule, I think writing means specifying L in the option [] that you want to add to the end of RewriteRule.
This option [L] means that if the conditions are met, the decision will end there (that is, it will not evaluate the RewriteRule that follows).

Therefore, by bringing this option to the beginning of a set of rules, URLs that match the rule can exit without reaching the transfer process and exclude the specified URL access from the transfer configuration.

RewriteEngine On
RewriteBase/
RewriteRule^/shoki2/wp-admin/-[L]
RewriteRule^/shoki2/test1/http://example.co.jp/test1/ [R=301,L]
RewriteRule^/shoki2/test2/http://example.co.jp/test2/ [R=301,L]
RewriteRule^/shoki2/test3/http://example.ne.jp/test3/ [R=301,L]
RewriteRule^/shoki2/test4/http://example.ne.jp/test4/ [R=301,L]
RewriteRule^/(.*)$http://example.com/$1 [R=301,L]

At the beginning

RewriteRule^/shoki2/wp-admin/-[L]

After you finish the rule in , you might want to set the transfer rule.