There is a supported method of doing this, you need some tools which I believe are in the exchange resource kit. Let me know if you have trouble getting them.
the files are profgen.exe, newprof.exe and a .prf file. we run it as a logon script for new users, the syntax being
if not exist "%userprofile%\Local Settings\Application Data\Microsoft\Outlook\outlook.ost" profgen.exe newprof.exe -P outlook.prf -R -N -U
Note thats all on one line. The prf file contains the customised outlook settings that you want to apply when the profile is generated, and uses the %username% variable as your previous respondent mentioned. Im guessing that the previous respondent hasn't tried to distribute outlook (at least 2000) with a transforms file as hesuggests - its buggy as hell. searching on technet may give you more info on profgen, I haven't tried looking myself.