Redirect rule case insensitive - .htaccess

Question

I have URL rewrite rule:
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^/sites/
RewriteRule ^([^/]+)/?(.*)$ sites/$1/$2 [NC,L]
When this URL is called: http://example.com/suyash
It internally calls http://example.com/sites/suyash but keeps the URL as http://example.com/suyash only. Please note that the folder sites/suyash actually exists
The issue I am facing is that when I call a URL: http://example.com/Suyash (Uppercase) it shows a 404 error.
When I use the mod_speling module and add the following to the code:
CheckSpelling On
and now when I call http://example.com/Suyash it changes the URL to http://example.com/sites/suyash
How do I get it to only change URL from http://example.com/Suyash to http://example.com/suyash?

Answer 1

mod_speling will redirect the browser in order to fix spelling, there's no way to avoid this. The only thing I can think of is to try proxying the request internally by using the P flag. You'll need to make sure you have mod_proxy loaded. I haven't tested this:
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^/sites/
RewriteRule ^([^/]+)/?(.*)$ sites/$1/$2 [NC,L,P]

Answer 2

I would say keep CheckSpelling off.
And then have your rule like this:
CheckSpelling Off
RewriteEngine On
RewriteBase /
RewriteCond %{DOCUMENT_ROOT}/$0 -f [NC]
RewriteCond %{DOCUMENT_ROOT}/$0 -d [NC]
RewriteCond %{REQUEST_URI} !^/sites/ [NC]
RewriteRule ^([^/]+)/?(.*)$ sites/$1/$2 [L]