I couldn't find english version of microsoft knowledge base info
here is japanese version but this one have answer.
http://support.microsoft.com/default.aspx?scid=kb;ja;883685
this document say,
create personal folder on outlook 2003, use for outlook 2000
export outlook 2003 data to this newly created personal folder(backup)
copy this backup folder to PC which runing outlook 2000
Open this file from outlook 2000
* how to create personal folder for oulook 2000 on outlook 2003
start outlook 2003
select from outlook 2003 menu, file > outlook data file
click add
you may have warning on create none unicode profile, but click ok
create pst file(any location, any file name are fine)
click ok
give name to this pst file
how to export
use export from outlook 2003 menu (file > import and export)
etc.
something like web site below
http://translation.langenberg.com/
good luck