Use web lookups to redirect to different page

Hi. I am looking to do the following:

I have a form that can only be filled out once. This form will save to a custom data object. What we want is that if someone comes back to the form, either from a link in an email or directly, they should be redirected to a page saying they have already filled in the form and can not do so again. I am pretty sure this can be done using a Visitor lookup to pull the email address of the visitor and then using a datacard lookup we could see if that email address has filled in the form