get pid from popen3 or get redirection in execl

[Yu Wang]

Hi,all
   Does "execl", or whatever this family, support redirection of output?
   Say, I have a script: ( on my Linux7.2,C shell environment,with 
python2.2.1)

command="somecommand"
arg="-i somefile > output file"
execl(command,arg)

what's wrong with this?

And,
    how could I get child pid from "popen3(somecommand)".

Thanks to you.
Regards.