htaccess rewrite to replace domain

[MTWKApplied]

Thought this would be simple but nothing I've tried is working. We built this wordpress site. Before it went live, it got indexed so I'm getting the following:

http://s152979.gridserver.com/recent_projects/

When I want to see:
http://www.neponsetvalleyconstructio...cent_projects/


The site works but we would like to have the second url display even if viewer has come in through the first link. I've been trying to work the htaccess file but NOTHING I've tried works. This is the last suggestion that was made to me. It also doesn't work. Does anyone know how to do this?

Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} s152979.gridserver.com/ [NC]
RewriteRule ^(.*)$ http://www.neponsetvalleyconstruction.com/$1 [R=301,L]

[kelisaid]

For the general settings on the admin screen what do you have in WordPress Address (URL) & Site Address (URL)?

[Inigoesdr]

Neither site is coming up at the moment. Try removing the slash from the end of your RewriteCond and make sure you have your site URLs updated as kelisaid mentioned.