[Michael.A]

RewriteEngine on
RewriteCond %{HTTP_HOST} ^(www\.)?ur site goes here.com/phpmyadmin/$ [NC]
RewriteCond %{REQUEST_URI} !^/phpmyadmin/
RewriteRule ^(.*)$ "http://ur site goes here.com/phpmyadmin/" [R=301,L]

RewriteCond %{HTTP_HOST} ^(www\.)?ur site goes here.com$ [NC]
RewriteCond %{REQUEST_URI} !^/forum/
RewriteRule ^(.*)$ "http://ur site goes here.com/forum/" [R=301,L]

if u want u can do the same for the cpanel http:// ur site goes here.com/capnel/
just add this

RewriteCond %{HTTP_HOST} ^(www\.)?ur site goes here.com/cpanel/$ [NC]
RewriteCond %{REQUEST_URI} !^/cpanel/
RewriteRule ^(.*)$ "http://ur site goes here.com/cpanel/" [R=301,L]