How Would I Do Something Like This?

Hey all:

I'm currently building a form builder in Yii where the front end consists of a drag and drop interface. The user can drag as many text, text area, check lists, and radio lists as they desire. The interface would allow the user to make any field required. I've built most of the system until I got the the validation portion of my project. Somehow I thought I could use the scenarios but I cant figure out how to dynamically bind a rule to a input field that I did not name. Any suggestions on how I could approach this?

Thanks