portable subprocess with return value and path search

[Joshua Levy]

I'm trying desperately to get python to do the following
four things at the same time:
    1. Run a subprocess (like "java com.foo.bar arg")
    2. Get the process return value from that subprocess
    3. Work on both Windows and UNIX  (I'll settle for 
          post-Win2000 and Solaris/Linux.)
    4. Resolve the executable, based on the current path.
       (So I only need "java", and not "c:\jdk1.2.2\bin\java",
       in the example above.)
Os.system does not return values from Windows.  The versions of
Os.spawn on Widnows do not resolve executables.
Thanks in advance for any help.

Joshua Levy