running textpad/java tools off a flashdirve via U3

I've got it set up right now to allow me to run textpad off my flashdrive
i can compile and run applications/applets when I'm on a computer that has the JDK installed

so I tried installing the JDK on my flash drive and running it off there and it worked for compiling and running applicatoins but I can't get the applet viewer to work

I don't care so much weather I can get the applet viewer working but I do need to figure out a way in the options to access javac.exe and java.exe off the flash drive when I don't know what drive its in
when I go to different computers the drive is chosen automatically, so the destination of the JDK changes

i'm not sure how else to explain what I need so, plz help me out here, I'm going to be working on many different computers at school that will not have the JDK installed and this was my best idea to solve it, and its works great
except i need to change the destination of the jdk again and again

 

ha figured it out myself
just replace the drive name like "g:" with "%U3_DEVICE_PATH%"
and you're all set

 

now it doesn't work anymore
it only works that way on that computer
so it must be saving those settings in the wrong spot

anybody got a clue what to do?