Getting returncode of a command executed with Popen through xterm

[AmFreak at web.de]

Hi,

i have a program that have to execute linux commands. I do it like this:

retcode = Popen(["xterm", "-e", command],stdin=PIPE, stdout=PIPE,  
stderr=PIPE)

I have to use xterm because some commands need further input from the user  
after they are executed.
But when i use xterm i can't get the returncode or the errormessage from a  
command:

print retcode.returncode				# always 0
print retcode.stderr.read()			# always empty
print retcode.stdout.read()			# always empty

The same code works without xterm. As i understand it, if i use xterm the  
retcode refers to the xterm window (process).
But is there a way i can get the returncode and errormessage of the  
command i sent to xterm ?

Thanks for any answers

AmFreak