script - Set Permanent Environmental Variable in Windows XP

I want to set environmental variables permanently through a batch file. Is there a command to set Permanent Environmental Variable (other than SETX) for Windows XP service pack 3?

command SETX JAVA_HOME="C:\java\jdk-1.4" is not supported in my machine. It is Windows XP service pack 3.

Answer

Per user settings command line:

% reg add KEY  /v JAVA_HOME /t REG_SZ /d "C:\java\jdk-1.4"

For user only settings replace KEY with:

HKCU\Environment

For per machine settings replace KEY with:

HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment

(Attention: there is a space in the last key, quote it with " !)