mystartup.bat: how to control tomcat environment variables?

here is an example of myservice.bat


@rem mystartup.bat
@set CATALINA_HOME=c:\satya\i\tomcat632
@set JAVA_HOME=c:\satya\i\jdk1632
@set JAVA_OPTS=-Xms128m  -Xmx512m
@set exe=%CATALINA_HOME%\bin\catalina.bat
@call %exe% run %1 %2 %3 %4