set hidden field values in form during json request?

set hidden field values in form during json request?

I'm jquery-ui autocomplete for my MVC5 project.
This is what i'm doing in view
  2.             using (Html.BeginForm("AddAttendee"))
  3.             {
  4.                 @Html.HiddenFor(m=>m.SelectedEmail.FirstName)
  5.                 @Html.HiddenFor(m=>m.SelectedEmail.LastName)
  6.                 @Html.HiddenFor(m=>m.SelectedEmail.AppointmentId)
  7.                 @Html.HiddenFor(m=>m.SelectedSuperOfficeEmail.PersonId)
  8.                 <div class="form-group">
  9.                     @Html.LabelFor(m => m.SelectedEmail.Email, new { @class = "col-md-2 control-label" })
  10.                     <div class="col-md-8 input-group">
  11.                         @Html.TextBoxFor(m => m.SelectedEmail.Email, new { id = "SelectedSuperOfficeEmail", @class = "form-control", PlaceHolder = "Search in SuperOffice" }) <input type='submit' id="btnEmail" class="btn btn-default" value="Add>>" />
  12.                     </div>
  13.                 </div>
  14.                 
  15.             }
and in controller
  1.         public JsonResult SuperOfficePerson(string term)
            {
                var persons = _connectionRepository.FindPersons(term);
                return Json(persons.Select(p => new { label = p.FirstName + " " + p.LastName, value = p.Email,p.FirstName,p.LastName,p.ExternalPersonId}), JsonRequestBehavior.AllowGet);
               
            }
In browser when I check the response, I get the required values as result. For example
  1. [{"label":"test user","value":"test.user@hotmail.com","FirstName":"test","LastName":"user","ExternalPersonId":6}]
Now how do I bind the Firstname, lastname, etc values to my hidden field in my view? Is that possible?