using restful rails but need to alter the widgets/new page

To all:

hi,

i am currently folllowing restful rails in my implementation.

however i am still using 1.2.6 due to time constraints.

currently i have a widget controller that has a new and create functions

the new function clearly will be GET /widgets/new the create function will be POST /widgets/create

now the issue is this.

i need to create a link in another part of my application that will be pointed to the new widget form page.

the only difference is this link will then result in the new widget form to have some of its parameters already filled up.

for eg if widgets/new will result in a form that has parameters A, B, C waiting to be filled up by the user.

however i need a link where it will direct to a form where the parameter A is already filled up depending on where the link is.

I need the current widgets/new which requires user input in parameters A , B , C but i also need this extra link as well.

i dont wish to create another get and post function since the current one is working quite fine. I was wondering if there is a way to tweak it to get what i want.

thanks!