Redirect os.system output

[jas]

I would like to redirect the output from os.system to a variable, but
am having trouble.  I tried using os.popen(..).read() ...but that
doesn't give me exactly what i want.

..this is windows by the way.

For example:
tmp = os.popen("hostname").read()

...works as expected.

however,

tmp = os.popen("cmd").read()
...i would like to have access to the cmd process...i.e. enter commands
like a normal command line. os.system() allows this, but i dont want
output to the screen..i wanna store it to a variable.  then send
content of variable elsewhere,  receive more input and submit it.
almost emulate the windows command prompt.

any ideas?