store method in dictionary to execute later given a type

Is it possible to do the following based on a given type:

var myTypes = new List<Type>();//contains list of classes that implements ISameInterface

public class MyType : ISameInterface
{
    public string GetDescription(int num)
    {
    }
}

var result = new Dictionary<Type, Func<int, string>> ();

this is the idea I have but don't really know how to add the expression created to the dictionary

foreach(var t in myTypes)
{
    var exp = Expression.Call(Expression.Constant(Activator.CreateInstance(t),
        t.GetMethod("GetDescription"))
    result.Add(t, exp????);

}