Create routeValues (anonymous type) programmatically in ASP.NET MVC 3

Assume we have a page that include some elements to support search from DB, so in Post Action we need to find which elements are active and according to that create route values something like this:

List<Parameter> SearchParameters = GetFilterParameters(collection);


if(SearchParameters.Count > 0)
foreach(Parameter item in SearchParameters) {

    switch(item.Name) {
                    case "Category":
                    CategoryValue= item.Value;
                        break;

                    case "StartDate":
                    StartDateValue= item.Value;
                        break;


                    case "Product":
                    ProductValue= item.Value;
                        break;

                }
return RedirectToAction("Index", new {category = CategoryValue, startdate=StartDateValue, product=ProductValue });

So is there any way to define routeValues dynamically something like the followings Pseudo-Code:

var dynamicRoutValues;
foreach(Parameter item in SearchParameters) {

  dynamicRoutValues.Add(item.Name, item.Value)

}

    return RedirectToAction("Index", dynamicRoutValues);