This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
No because the value of the variable you have is not set till runtime. Whereas the configuration is during development time, meaning you can't set a value in the configuration to a value that isn't set till runtime.