Forum Moderators: phranque
You should instead redirect that request to the canonical format of your choosing. All lower case is usually the best way to have your URLs. Use a 301 redirect.
You can use a RewriteMap, and your host will need to define that in httpd.conf for you, and activate it, if you don't have access to do it yourself.
The links within your site should use the format that you want users to see. Links 'define' URLs.
There are several recent and current threads with {tolower} examples within that can get you started.
Warning: The code is complex, and must be considered as a whole; You cannot just take one snippet out of the middle and expect it to work. It is an "advanced topic" and not for the faint of heart or those not completely confident in their mod_rewrite interpretation and implementation skills; Otherwise, it will likely require more "support" than this forum can supply...
Jim