How to keep old rewrite rules ?

Hello,

I currently have that in my .htaccess :

Code:

Options +FollowSymlinks
RewriteEngine on

RewriteRule ^perso/(.*)$ test.php?username=$1 [L]
RewriteRule ^perso/(.*)$ test.php?username=$1 [L]

RewriteRule ^comparateur/([0-9]+_[a-z0-9_]+(_.+)?\.html)$ /comparateur.php?rw=$1 [L]
RewriteRule ^comparateur/([a-z0-9_]+/p[0-9]+_[a-z0-9_]+\.html)$ /comparateur.php?rw=$1 [L]
RewriteRule ^concours-photo.php http://www.virusphoto.com/index.php?page=concours [L]
RewriteRule ^annuaire-photo.php http://www.virusphoto.com/links/ [L]
RewriteRule ^links/register.php? http://www.virusphoto.com/register.php [L]
 
ErrorDocument 404 /404.php

I'd like to keep that.
Is it possible ?
Where can I add the VBSEO rewrite rules ?

Thanks.

Ok thanks.