Calling external programs from D

[Tydr Schnubbis]

I'm making a gui app with DWT, and I need a way to run an external, 
command line tool and get its output.  Either directly from the tool's 
stdout, or by having it write to a file first.

I'm working on windows.  The system() function is unusable because it 
opens a new command line window when it starts the tool.  That you can 
get it to close the window again really fast by using 'start' is not 
good enough

It doesn't have to be a portable way.  If someone can tell me how to 
call _popen or something in msvcrt.dll, I would be happy.