Hi! This looks more like a question for IBM.
However, you can change manually the file on each node!
If this seems to ugly, you can change the cache properties in the program, but as you used urgent in your post..maybe this will take u more time.
I think is better to change it manually! (While you test the solution with program)
I hope this help you, I am assuming that u are using WAS 5 isn't it? Be carefull because the configuration files are read from a different place where the ear is expandend.