I think you probably mean the PATH. In Unix, this is the PATH environment variable. In Windows, you can SET this using the "SET PATH=" statement or the older DOS PATH command OR set it globally using the Windows Control Panel System applet.
In Windows, BTW, instead of using a dollar sign, you bracket environment vairables with "%". So instead of "echo $JAVA_HOME", you'd write "echo %JAVA_HOME%".
An IDE is no substitute for an Intelligent Developer.