Back-ticks work just fine in capturing console output, and do not pop up a console window.

If your Perl process is not already associated with a console window, then backticks or open "cmd|" do open a new console window.

I played around a little trying to get I/O redirection to work using the normal Perl IO constructs and/or POSIX dup2, but it didn't work. I see this Python program to solve the problem. This should be translatable to Perl.

The only other hint I have is that there is already a Win32::Process module, so you don't have to call CreateProcess using Win32::API.