g1smd - 11:13 pm on Jan 10, 2013 (gmt 0)
The redirects need the hostname stated as without it you will end up with a multiple step redirection chain for some requests.
This is where one rule fixes a problem then another rule fixes a different problem and then the non-www/www rule fixes the hostname. So having requested a URL, there's then several redirects each generating a new request before the content is finally delivered at the last requested URL. This is a problem.
RewriteRule ^laplume/$ /laplume/cms/index.php [L]
If you requested
example.com/laplume/ AND there's a file inside the server at
/laplume/cms/index.php and the script is able to detect that
/laplume/ was requested and it has some content to deliver for that request, then it should work.