modyfing functional forms with Discover and contraints with Forcite

Hello everybody

I was wondering if there was the possibility of:

1) modyfing the functional forms of Discover "free" forcefields (in cvff, for example, changing the bond stretching into a cubic potential).

2) applying geometrical costraints (something like RATTLE in Discover) to a ForcitePlus Calculation

Thanks in advance for replies

Regards

Giulio