I discovered, a method that no need to spend too much your time to build a new Window. And more importantly, it just requires two code. Then your program is totally ready!!!!
To do this, a few steps everybody :
Step 1 : Create a dialog (Resource).
Remember the dialog Id. Build all controls for this dialog.
Step 2 : Build a new WinProc for this dialog. You may make only a new skin, and then, you may consider about messages handing and fancy stuff later.
Step 2 : Start your program instantly (using DialogBoxParam)
Step 3 : Handle all messages. Remember to close dialog (EndDialog).
Only a few tiny steps you'll get a new WinApi program. Simple? Fast? Convenient? What do you think?