Where to add redirect code in .htaccess?

[Stratcat]

This is a newbie question:

I've read a lot about adding 301 redirect code to the .htaccess file in order to fix the problem of search engines mistaking www and non-www domains as duplicate content.

For example - according to Google analytics - Google currently thinks I have 3 domains all with duplicate content:

mydomain.com
MyDomain.com (Each word capitalized)
www.mydomain.com

My question is, does it matter where in the .htaccess file you place the redirect code? Is there a proper order that the various directives need to be in?

The code I'm going to use is:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^mydomain.com$ [NC,OR]
RewriteCond %{HTTP_HOST} ^MyDomain.com$ [NC]
RewriteRule ^(.*)$ http://www.mydomain.com/$1 [R=301,L]

Do I have the code correct and should I place it somewhere at the top of the file, at the bottom, or somewhere in between?

Everything I've read - from the apache docs to various forums - all just say to add the lines of code. No one ever says where to place it.

Any help would be appreciated,
Dean

[Stratcat]

For the benefit of any other newbies out there who may read this post...

The answer is, no, it doesn't matter what order the directives are placed in the .htaccess file.

And the code I finally went with is:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^example.com [NC]
RewriteRule ^(.*) http://www.example.com/$1 [R=301,L]