Print Preview (again?)

Hi
I'm getting very confused with trying to draw a small print preview box. I'm
trying to draw fonts the exact proportionate size. Because I can't show
fractional font sizes on screen, I'm trying to draw it into a memory DC
(quite big?) then StretchBlt it down onto my box (I don't mind if it's a
bit pixelly as long as it's in proportion).
This code works after a fashion but what do my values need to be? Do I need
to set the map mode to a higher value? It comes about 1/3 size.
Thanks for any advice,
Greg Chapman

void CA4Page::OnPaint()
{
 CPaintDC dc(this);
 CDC memDC;
 memDC.CreateCompatibleDC(&dc);
 // ??? memDC.SetMapMode(MM_HIMETRIC);
 int deviceRes = memDC.GetDeviceCaps(LOGPIXELSY);

  CRect rect;
 this->GetClientRect(&rect);
 // this is roughly 210 x 297 ie a mm to a pixel

 CRect memRect(0,0, 2100, 2970);
 // nice big one for best resolution?

 CBitmap bmp;
 bmp.CreateCompatibleBitmap(&memDC, memRect.Width(), memRect.Height());
 memDC.SelectObject(&bmp);

 LOGFONT fontStruct;
 // this fills out the struct
 Utilities::FillFontStruct("Times New Roman", 0, 0, 4, fontStruct);

 CString str("Hello World");

 CFont font;
 int pointSize = 60;

 fontStruct.lfHeight = (int)-MulDiv(pointSize, deviceRes, 72);
 font.CreateFontIndirect(&fontStruct);
 memDC.SelectObject(&font);
 memDC.DrawText(str, memRect, 0);

 dc.StretchBlt(rect.left, rect.top, rect.Width(), rect.Height(),
              &memDC, 0, 0, memRect.Width(), memRect.Height(),
              SRCCOPY);
}