No. If the ONLY thing you want is the non-www to www redirection only copy these lines:
########## Begin - Redirect non-www to www
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]
## If the above throws an HTTP 500 error, swap [R=301,L] with [R,L]
########## End - Redirect non-www to www
into your existing .htaccess file, after your RewriteBase line.
If you want to include all the security features of the Master .htaccess you can use Admin Tools Porfessional's .htaccess Maker. That's what it does. BUT! Before trying to use .htaccess Maker you need to do some reading. Make sure you have read the documentation and understand that some things may break and you'll have to do some very easy debugging to fix them, exactly as mentioned in the documentation. The .htaccess Maker (and the Master .htaccess upon which it is based) are very potent.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!