Which directory should I place my htaccess file for this redirect

Hi

I want to redirect:

http://www.website.com/subdir/pages/ref1/
to
http://www.website.com/subdir/pages/ref2/

How would I do that and which directory should I place the htaccess file in?

Thanks

You can place the .htaccess in the root directory of your website and it should work.