A question about IDLE and environment variables

[Tristan]

Hello community:
I post this because I could not find satisfactory answers in the posts
generated by this nice group.
I work on winXP. I have many little python applications in different
folders, each application can share or not other objects located in the
same or other folders.
The way I work to use these applications is:
1) For almost everyone, I execute a corresponding ".bat file" into
which I define and/or include values for some "temporal"
environment variables that let me find all the objects that the
selected application uses. Sometimes I include in the .bat file the
execution of the application, but generally I leave in a prompt status,
ready to invoke python or some dos commands.
2) When I close the command prompt window, there are no traces of my
enviroment variables in my windows system (that is right). Only the
default windows environment variables remain.

I tried to do the same with the IDLE (and I imagine tha same occurs
with Python command line), but I have the next problem:
I can not find in IDLE (or another app?) the way to previously define
and/or include automatically values for my "temporal" environment
variables as I do in the .bat files. The use of Control Panel -System
-Advanced is tedious to use as, my enviroment variables values are
"temporal".
Any advice, please???