Hi. Well I am sure you can do it but getting the specific client side code would either require knowledge of javascript or implementation hours from our team though (or maybe community support here). Basically I am sure it 'can' be done using the new client side events feature of javascript and Dynamic Forms.
A few things...
1. We recently posted demonstrations that cover client side events and so forth. These have many features to them such as calculating a checkbox group for a total, or other properties such as hiding html or copying field values.
2. Specifically related to Radio Button fields we just setup a demonstration for another client wanting to know how to reference fields from a radio button with the javascript client side events feature.
3. Within any of these javascript/client side event features you could easily set a hidden field property equal to the results of a client side function call etc... For example $(HiddenField) = yourcustomjavascriptfunction(); etc...
4. There is an option within the Dynamic Completion Events (all completion events such as adding the user to a role, redirecting the user, firing off an email, processing a SQL statement, etc...) to process this event based conditionally upon a form value. So you could setup an event to proces where the hidden field is equal to 'C' and that user would be redirected to another page as other users, you could then setup one for 'B', etc...
So... Yes I think that it can be done but again it might require some more hands on tweaking of the client side javascript functions that already come out of the box with the product. Please feel free to post questions or try and get your example up on www.betasprings.com.
Hope you find this helpful!
-Chad