I'm confused with win32pipe

[Pedro Vale Lima]

I need to run some commands on a win98 computer and I'm
having some problems to understand win32pipe behavior

If I write

     (pin, pout) = win32pipe.popen4(r'copy c:\tmp\*.* c:\tmp2\','t')

the script copies some of the files (not all!).

I have some questions. The first is where can I find more documentation
for win32pipe (the pythonwin reference is very short) ?.
Is the process run in a subprocess? What's the meaning of the 't' and
'b' flags?

Thanks for the attention,

pedro lima