.htaccess redirect to .www, subfolder, hide subfolder and index.php

Question

I'd like to use .htaccess to redirect all requests to the www. version of the domain, and to the files stored in a "new" subdirectory of the root. However, the "new" subdirectory should be hidden and also any index.php occurance in the URL. Is this possible? Example: http://mydomain.de/?x=100 would direct to http://www.mydomain.de/index.php?x=100 , but only show http://www.mydomain.de?x=100 in the browser.

So far I tried it with

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d [OR]
RewriteCond %{HTTP_HOST} ^(www\.)?mydomain\.de$
RewriteRule ^new/index.php(.*)$ /$1 \
RewriteRule (.*) http://www.mydomain\.de/new [R=301,L]

but that doesn't work.

Edit w/ latest code, I've commented out the lines that led to a server error:

# add www
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [R=302,L]
# remove /new/ from URL
# RewriteCond %{THE_REQUEST} /new/(\S*)\s [NC]
# RewriteRule ^ /%1 [L,R=302]  
# remove /index.php from URL
RewriteCond %{THE_REQUEST} /index\.php [NC]
RewriteRule ^(.*?)index\.php$ /$1 [L,R=302,NC]
# redirect everything to /new/
RewriteCond %{HTTP_HOST} !^/?$
RewriteRule ^((?!new).*)$ http://www.xn--krisen-lsen-yfb.at/new/$1 [L]
# RewriteCond %{REQUEST_FILENAME} !-f
# RewriteCond %{REQUEST_FILENAME} !-d
# RewriteRule !^new/ new%{REQUEST_URI} [L,NC]

With the above htaccess code, "/new" and "index.php" still remain in the URL. Also, redirect to "www." doesn't work if the URL contains parameters, like in " http://krisen-lösen.at/new/index.php/das-team ".

Answer 1

Have it like this in your site root .htaccess:

RewriteEngine on

# add www
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [R=302,L]

# remove /new/ from URL
RewriteCond %{THE_REQUEST} /new/(\S*)\s [NC]
RewriteRule ^ /%1 [L,R=302]  

# remove /index.php from URL
RewriteCond %{THE_REQUEST} /index\.php [NC]
RewriteRule ^(.*?)index\.php$ /$1 [L,R=302,NC]

# route everything to /new/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule !^new/ new%{REQUEST_URI} [L,NC]