Evaluate a String that contains code

Question

Is there a way to evaluate a string that contains code. I am wanting to store "Meta Data" in a database and then when the data is read out I want it to be evalulated before the result is rendered. For example lets say I have an onclick event stored in the database. The value of the onclick event is toggle('Car.Engine') where Car.Engine is an accessible object. How can I make the compiler eval the string before it puts the value in the toggle function?