Você poderia apenas saltar as 3 réguas quando o HTTP_HOST é test.mysite.nl por exemplo.
RewriteEngine sobre
RewriteBase/
#
# as seguintes “3” réguas não se aplicam a test.mysite.nl
% de RewriteCond {HTTP_HOST} test.mysite.nl
RewriteRule. * - [S=3]
#
RewriteCond % {REQUEST_URI}! (\. |/$)
RewriteRule (. *)
http://www.mysite.nl/$1/ [R=301, L]
#
% de RewriteCond {HTTP_HOST} ^mysite.nl$
RewriteRule ^/? (. *) $
http://www.mysite.nl/$1 [R=301, L]
#
RewriteCond % {REQUEST_URI}! ^/production
^ de RewriteRule (. *) $ production/$1 [L]