Using environment variable in log4j.properties

[Durham David R Jr Contr 805 CSPTS/SCE]

Will using something like this work:
 
    log4j.appender.app.File=${APP_HOME}\TIDEII_app.log
 
Assuming that APP_HOME is a system variable on a windows server?
 
Is this enough information to answer this question?
 
 
Thanks,
 
Dave