HTACCESS Question

[eluser]noideawhattotypehere[/eluser]
well i guess your folder structure looks like that
/root
----index.php - main site
----htaccess - lets call it main_one
----rnd02
--------rnd02
------------index.php
------------htaccess - submain_one

So basically what you need is add a rule in main_one not to rewrite anything when url is domain.com/rnd02/*, it works when you add index.php cuz there is a condition not to rewrite if you request a file. Otherwise every request is routed to main sites index.php.