RewriteEngine on

# If the hostname is not www.cafecamp.com...
RewriteCond %{HTTP_HOST} !^www\.cafecamp\.com$ [NC]
# ...and it matches this...
RewriteCond %{HTTP_HOST} ^(([-_a-z0-9]+\.)+)cafecamp\.com$ [NC]
# ...redirect the user and discard the original uri
RewriteRule ^ http://www.cafecamp.com/camp.php?c=%1 [L,R=301]