Nach links geht ja so:

/////Benötigt für Fenster Positionierung
	CRect myRect, desktop;
	GetDesktopWindow()->GetWindowRect(&desktop);
	GetWindowRect(&myRect);
	MoveWindow(0, (desktop.Height()/2) - (myRect.Height()/2), myRect.Width(), myRect.Height());

Danke für eure Hilfe.

der dialog läst sich damit zur laufzeit des programms über den bildschirm schieben

defines kommen in die header

#define SHOW_MAXIMIZED		0
#define SHOW_WINDOWHALF_LEFT	1
#define SHOW_WINDOWHALF_RIGHT	2
#define SHOW_WINDOWHALF_TOP		3
#define SHOW_WINDOWHALF_BOTTOM	4
#define SHOW_WINDOWHALF_TOPLEFT	5
#define SHOW_WINDOWHALF_TOPRIGHT	6
#define SHOW_WINDOWHALF_BOTTOMLEFT	7
#define SHOW_WINDOWHALF_BOTTOMRIGHT  8

dann erstell dir ne funktion die du per Button oder aus der OnInit oder so ansprichts dort schreibste folgenden code rein

WINDOWPLACEMENT wp;
GetWorkingArray(&wp,SHOW_WINDOWHALF_TOPRIGHT);
SetWindowPlacement(&wp);

erstell dir dann die funktion

void GetWorkingArray(WINDOWPLACEMENT *wp, UINT uiShow)

dort kommt dann folgender code rein

CRect WorkArrayRect;
	//////////////////////////////////////////////
	//Ermitle Bildschirmgröße abzüglich Taskleiste
	SystemParametersInfo(SPI_GETWORKAREA,0,&WorkArrayRect,0);
	int nBottom=0,nTop=0,nLeft=0,nRight=0;
	nBottom = WorkArrayRect.bottom;
	nTop	= WorkArrayRect.top;
	nLeft	= WorkArrayRect.left;
	nRight	= WorkArrayRect.right;

		switch(uiShow)
		{
			case SHOW_MAXIMIZED:
				nBottom = WorkArrayRect.bottom;
				nTop	= WorkArrayRect.top;
				nLeft	= WorkArrayRect.left;
				nRight	= WorkArrayRect.right;
			break;
			case SHOW_WINDOWHALF_LEFT:
				nRight	= WorkArrayRect.right-(WorkArrayRect.right/2);
				break;
			case SHOW_WINDOWHALF_RIGHT:
				nLeft	= WorkArrayRect.left+(WorkArrayRect.right/2);
			break;
			case SHOW_WINDOWHALF_BOTTOM:
				nTop	= WorkArrayRect.top+(WorkArrayRect.bottom/2);
			break;
			case SHOW_WINDOWHALF_TOP:
				nBottom = WorkArrayRect.bottom-(WorkArrayRect.bottom/2);
			break;
			case SHOW_WINDOWHALF_TOPLEFT:
				nBottom = WorkArrayRect.bottom-(WorkArrayRect.bottom/2);
				nRight	= WorkArrayRect.right-(WorkArrayRect.right/2);
			break;
			case SHOW_WINDOWHALF_TOPRIGHT:
				nBottom = WorkArrayRect.bottom-(WorkArrayRect.bottom/2);
				nLeft	= WorkArrayRect.left+(WorkArrayRect.right/2);
			break;
			case SHOW_WINDOWHALF_BOTTOMLEFT:
				nTop	= WorkArrayRect.top+(WorkArrayRect.bottom/2);
				nRight	= WorkArrayRect.right-(WorkArrayRect.right/2);
			break;
			case SHOW_WINDOWHALF_BOTTOMRIGHT:
				nTop	= WorkArrayRect.top+(WorkArrayRect.bottom/2);
				nLeft	= WorkArrayRect.left+(WorkArrayRect.right/2);
			break;
		}

	wp->rcNormalPosition.bottom = nBottom;
	wp->rcNormalPosition.top	= nTop;
	wp->rcNormalPosition.left	= nLeft;
	wp->rcNormalPosition.right	= nRight;
	wp->showCmd = SW_SHOW;

viel spaß damit
mfg
LowFly

...
GetSystemMetrics(SM_CXSCREEN);
GetSystemMetrics(SM_CYSCREEN);
...