How modify the language of the WebSphere Application Server log

Yesterday i was on a customer site and all Portal Servers are installed on Windows Servers. The language settings are set using policies and the logs are in Brazilian Portuguese. Too bad for troubleshooting.
So i change the language to English using the following:

Append the following to the existing value for the property "Generic JVM arguments": -Duser.language=xx -Duser.region=YY

where xx and YY values are dependent upon the desired language.

For English US the values are bellow

-Duser.language=en -Duser.region=US