Need help with a redirect issue

Hello..

I have a client that has hard-coded links within his content (like 4000 pages) We need to point those links to a cloned dev environment on his root domain.

So….we need http://coolwpsite.com/link/to/path to end up at

http://coolwpsite.com/DEVSITE/link/to/path

Would we do this through a 301 redirect in the .htaccess file?

//301 Redirect Entire Directory
RedirectMatch 301 /(.*) dev//$1

Does that look right?

Thanks!