Redirect index.php but not index.php?u=2

Is it possible to redirect, say, index.php, but not redirect index.php?u=4 or ANY url containing characters such as that?

I need desperately to do this, but I have yet to find a method. If anyone has an idea, I would greatly appreciate it

 

RewriteRule ^/index.php$ somewhere_else.php

 

thanks for the response!

unfortunately the snippet you posted doesn't work for me

 

Is this not possible?

 

Yep, it is possible. But you have to make directives for any URL that you want to redirect.

Redirect 301 /index.php http://theredirectedtobe.domain.com
Redirect 301 / http://theredirectedtobe.domain.com

and so on.

If you want to redirect particular parameters in URL, then you can use this

Options +FollowSymlinks
RewriteEngine On

RewriteCond %{QUERY_STRING} ^PHPSESSID [OR]
RewriteCond %{QUERY_STRING} ^f=
RewriteRule .* %{REQUEST_URI}? [R=301,L]

Code (markup):

Any parameter can be added.