__asm int 3

This causes the debugger to break.

Add this to the top of your WinMain:

while ( ::GetKeyState( VK_SCROLL ) );
   if ( GetProfileInt( L"ZumaCode", L"Debug", 1 ) ) __asm int 3;

When the program starts, it will wait at the first line (while statement), until the scroll lock key is turned off.

Next, if the [ZumaCode] section of the win.ini has Debug=1, then it breaks in the debugger. When the program isn't running in the debugger, Windows launches the debugger.