Short answer is, you can't. 

But! You can likely use the State Machine to accomplish what it is you're trying to do, if what it is you're trying to do involves taking a series of logical steps through the progression of a workflow that needs to work in different ways depending on the outcome of certain conditions within the workflow (or as a response to a task, etc.).

However, without more details or examples, it's difficult to help you beyond this text.