custom log4j appender not recognized on starting weblogic

[rushik]

I've created custom log4j appender for my application hosted in
weblogic environment.

If in log4j.properties I use any existing appender like console etc,
its working but the moment I put my custom appender, while restarting
its throwing "java.lang.NoClassDefFoundError"

My custom appender is not part of any package, its single class which
is part of "XYZAppender.jar" thus in my log4j.properties
I am using
log4j.appender.CAL=XYZAppender

I tried to put my appender jar almost all possible places like
CLASSPATH, /x/bea-wl92/user_projects/domains/testdomain/config/lib/
etc but still no luck.

I checked this type of threads, but couldnt see any given solution.

Please help.

--Rushik