Ciao,
se vuoi puoi redirezionare il sito. devi creare un file con nome .htaccess nella cartella principale (non in quella Joomla), dentro ci metti il seguente codice (naturalmente devi editare le informazioni con quelle del tuo sito: nome dominio, nome subfolder etc...). Se hai già un .htaccess nella cartella principale, aprilo e modificalo in modo che contenga il codice qui sotto.
# .htaccess main domain to subfolder redirect
# Copy and paste the following code into the .htaccess file
# in the public_html folder of your hosting account
# make the changes to the file according to the instructions.
# Do not change this line.
RewriteEngine on
# Change yourdomain.com to be your main domain.
RewriteCond %{HTTP_HOST} ^(www.)?yourmaindomain.com$ [NC]
# Change 'subfolder' to be the folder you will use for your main domain.
RewriteCond %{REQUEST_URI} !^/subfolder/
# Don't change these lines.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# Change 'subfolder' to be the folder you will use for your main domain.
RewriteRule ^(.*)$ /subfolder/$1 [L]
# Change yourdomain.com to be your main domain again.
# Change 'subfolder' to be the folder you will use for your main domain
# followed by / then the main file for your site, index.php, index.html, etc.
RewriteCond %{HTTP_HOST} ^(www.)?yourmaindomain.com$ [NC]
RewriteRule ^(/)?$ subfolder/index.php [L]