Newbie Q: PYTHONPATH_1 vs PYTHONPATH_2?

[engsol at teleport.com]

I have an "old" copy of Python on my NT machine. I've tailored
PYTHONPATH to know about myfiles and mylib, etc.

But I've now installed Python 2.1.1 in a different directory, and
would like to create PYTHONPATH_2, so as to not have to expand the
vanilla PYTHONPATH forever as new versions are available.

Is this do-able?

Thanks....engsol