El caso es que si pongo esa linea de código en htaccess no me sale la página, se queda en blanco.
Ten en cuenta que ya tengo varias lineas de código puestas en este archivo, y no controlo muy bien esto del htacess.
Mira, te dejo el código como si fuera nuevodominio.com ok?. A ver si tu sabes con esto que es lo que tendría que hacer para redireccionar bien.
Código:
# ~~start~~ Do not remove this comment, Prestashop will keep automatically the code outside this comment when .htaccess will be generated again
# .htaccess automaticaly generated by PrestaShop e-commerce open-source solution
# http://www.prestashop.com - http://www.prestashop.com/forums
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule . - [E=REWRITEBASE:/]
RewriteRule ^api/?(.*)$ %{ENV:REWRITEBASE}webservice/dispatcher.php?url=$1 [QSA,L]
# Images
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$1$2$3$4.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$1$2$3$4$5.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$1$2$3$4$5$6.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$1$2$3$4$5$6$7.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$1$2$3$4$5$6$7$8.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$1$2$3$4$5$6$7$8$9.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9$10.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^c/([0-9]+)(\-[\.*_a-zA-Z0-9-]*)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^c/([a-zA-Z-]+)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2.jpg [L]
# Dispatcher
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^.*$ - [NC,L]
RewriteCond %{HTTP_HOST} ^www.minuevodominio.com$
RewriteRule ^.*$ %{ENV:REWRITEBASE}index.php [NC,L]
</IfModule>
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
ExpiresByType text/css "access plus 1 week"
ExpiresByType text/javascript "access plus 1 week"
ExpiresByType application/javascript "access plus 1 week"
ExpiresByType application/x-javascript "access plus 1 week"
ExpiresByType image/x-icon "access plus 1 year"
</IfModule>
FileETag INode MTime Size
<IfModule mod_deflate.c>
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/javascript
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript
</IfModule>
#If rewrite mod isn't enabled
ErrorDocument 404 /index.php?controller=404
# ~~end~~ Do not remove this comment, Prestashop will keep automatically the code outside this comment when .htaccess will be generated again
Así no se me ocurre ninguna solución ahora. 
