This is the modifs i made in htaccess in order to have all my old pades redirected to my new cs cart first page.
RewriteCond %{REQUEST_FILENAME} !\.(png|gif|ico|swf|jpe?g|js|css)$
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /products\.php([?#][^\ ]*)?\ HTTP/
RewriteRule ^products\.php http://www.yourwebsite/? [L,R=301]
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /categories\.php([?#][^\ ]*)?\ HTTP/
RewriteRule ^categories\.php http://www.yourwebsite/? [L,R=301]
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /pages\.php([?#][^\ ]*)?\ HTTP/
RewriteRule ^pages\.php http://www.yourwebsite/? [L,R=301]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php?sef_rewrite=1 [L,QSA]
Hope this helps!