Moz 1.2.1 and OS8.6 preferences directory

I recently installed Mozilla 1.2.1 on my parents' PowerMac 7600 with
OS8.6, and am trying to fix a "bug" in the way it stores its settings.
 Upon starting Mozilla, it goes through some steps to either import a
profile from Communicator 4.80 or make a new one.  All of this works
just fine, and I can store profiles wherever I want, but two crucial
files (Application Registy and pluginreg.dat) always appear inside
Documents:Mozilla in the root hard drive area...and that's not
acceptable. :-(  I read a handful of threads about similar issues with
other OS's, maybe stemming from problems with an internal "Home"
variable, or in this case, maybe because the OS is 8.6 and lacks 9.x's
multiuser capabilities.  Still, there has to be a way around it.  Can
someone point me to particular Mozilla resource or support file
setting so I can change this directory to Hard Drive:System
Folder:Preferences:Mozilla or something else that's sane? :-)

Thanks,

Todd