.htaccess redirect if domain = x.example.com - apache

Question

I have a site on a subdomain:
x.example.com
I put it on a subdomain because it's running on a separate server from the main site.
Using proxy for apache, I have now moved the site to example.com/x/ I want to make a 301 redirect from the subdomain like this:
Redirect 301 / http://example.com/x/
but I don't know how to make sure that it does not result in a redirect loop, as the page i'm redirecting to contains the same htaccess-file (as it's a proxy of the old file)
this is what I tried:
RewriteCond %{HTTP_HOST} ^x.example.com$ [NC]
RewriteRule ^(.*)$ http://staging.example.se/x/ [R=301,L,NE]
this is my full .htaccess:
<IfModule mod_rewrite.c>
RewriteEngine On
#RewriteBase /
RewriteCond %{REQUEST_URI} ^(.*)//(.*)$
RewriteRule . %1/%2 [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^.*$ index.php?qa-rewrite=$0&%{QUERY_STRING} [L]
RewriteCond %{HTTP_HOST} ^zenqa.herokuapp.com$ [NC]
RewriteRule ^(.*)$ http://staging.zenconomy.se/faq/$1 [R=301,L,NE]
</IfModule>

Answer 1

You're missing a backreference, you need a $1 to get the original request and pass it along to the redirect:
RewriteCond %{HTTP_HOST} ^x.example.com$ [NC]
RewriteRule ^(.*)$ http://staging.example.se/x/$1 [R=301,L,NE]