How to execute a string as a function

1

Hi, I’m trying to make a function that can take a string formatted as a function command and execute it.
For example I want to take

 var myString:String = "runFunction(var1, var2, var3);"

and then execute that string as a function. I’ve tried

eval(myString);

and didnt seem to work. Anyone have ideas on how I can accomplish this? Thanks-