Is it standard/intended behaviour that the value of a hidden form field is not bound to the view model (nor is a query string value)?

Example:

<%= Html.Hidden("test", "13" )%>

if my poco view model contains a property test it should be bound shouldn't it?! i have to set it explicitely in the controller at the moment which kind of defeats the objective doesn't it?

bla( formviewmodel m, string test)
{
    m.test = test;
}

any feedback appreciated. thanks!

christian