Schau dir mal die WM_WINDOWPOSCHANGING an, dort kannst du in aller Ruhe die Z-Position des Fensters manipulieren.
Delphi-Quellcode:
typedef struct _WINDOWPOS { // wp
HWND hwnd;
HWND hwndInsertAfter;
int x;
int y;
int cx;
int cy;
UINT flags;
} WINDOWPOS;
Zitat:
hwndInsertAfter
Specifies the position of the window in Z order (front-to-back position). This member can be the
handle of the window behind which this window is placed, or can be one of the special values listed with the SetWindowPos function.