Java SE (Java Platform, Standard Edition)

We've got two web applications running running on Internet Explorer 6.0. App 1 runs with JRE 1.3.0_02 and App2 with JRE 1.4.3_07. Now the problem exists that because both JRE's are installed, only one can be used in Internet Explorer, but which one?

Is it possible to tell IE which JRE version to use when starting one session in the browser as compared to starting the other application with the other JRE version?

I have created a batch file that starts up IE and goes to the login screen of one of the applications, and trying to change the %JAVA_HOME% variable before it starts up:

set JAVA_Home=C:\Program Files\Java\j2re1.4.2_07
start iexplore http://fusion101:7001/CPG

But this does not work. The problem we are experiencing is that because IE uses version 1.3.0_02 by default, when the other app is started in IE (which uses 1.4.3_07) problems occur because of the versions that are clashing...

PLEASE PLEASE PLEASE HELP!!!!!!!!!!!!!!!!!