How can I hide the command line window?

["Lizhao" <jinmu190 126 com>]

Hello, every one
     Recently,I am writing a GTK+ program on windows platform that will call an external  program which is 
just a command line application with the function g_spawn_command_line_sync() . If I  run my program , the 
command line window flashes. My question is how I can run this external program in the background with the 
command line window hidden. Are there any other function I can use to solve my problem if this upper function 
isn't contributing. Sorry,My English is poor, but I am trying my best to make me understood!