How to create Action from text file on runtime c# MVC

Question

I have a project, that implements WorkflowEngine Designer. This library support adding Code Actions in ActionProvider, just like this: _actions.Add("MyAction", MyAction);

where second parameter is method name and _actions is a Dictionary<string, <Action<ProcessInstance, WorkflowRuntime, string>>>.

I can define this method in ActionProvider class, like this:

private void MyAction(ProcessInstance processInstance,
    WorkflowRuntime runtime, string actionParameter)
{
    var ss = "ss";
}

But what I need is Code Actions dynamically generated on runtime from text files outside the project. Those text files contains C# code and could be changed.

So how can I do this? Is it possible?