Solucion...
AddCharset ISO-8859-1 .iso8859-1 .latin1
RewriteEngine On
RewriteCond %{HTTP_HOST} ^dominio1.com|dominio3.com
RewriteRule (.*) http://www.dominio1.com/$1 [R=301,L]
RewriteCond %{HTTP_HOST} dominio2.com$
RewriteRule ^(.*)$
http://www.dominio1.com/en/page.php?node=70 [R=301,L]
Muchas gracias a todos los que respondieron :P