initialize log4j properties in mule 3 dynamically

I use mule 3.3.1 CE.

I have log4j_dev.properties for development environment. similarly , I have it for other environments.

I wonder if there is a way to initialize log4j properties based on current environment via mule

I asked this question in stackoverflow , waiting for an answer
http://stackoverflow.com/questions/17245198/initialize-log4j-properties-in-mule-3-dynamically

Can you take a look