NoCat opens all ports again!!! Help!!

Hello.

I would like to know how can I make NoCat only capture the user and just 
do captive portal splash instead of doing packet filtering?

I would like to do the filtering myself. I have a script to do so but, 
Nocat is opening all the ports and is not letting my script do the work.

What files do I need to edit to remove the forward rules NoCat uses?

Thanks in advanced for your help.