You will need to use low level Windows API functions. Example:

procedure TForm .Button Click(Sender: TObject);
var
  dc : hdc;
  MemDc : hdc;
  MemBitmap : hBitmap;
  OldMemBitmap : hBitmap;
begin
{Get the handle to the screen's dc}
  dc := GetDc(0);
{Create and retrieve a handle to a memory dc based on the screen}
  MemDc := CreateCompatibleDc(dc);
{Create a bitmap that is compatible with the display.}
{Note: if you pass "MemDc" to CreateCompatibleBitmap()}
{instead of "dc", you will get a monochrome bitmap!}
  MemBitmap := CreateCompatibleBitmap(dc,  00,  00);
{Release the screen dc}
  ReleaseDc(0, dc);
{Select the bitmap surface into the MemDc}
{remembering the default bitmap}
  OldMemBitmap := SelectObject(MemDc, MemBitmap);
{Draw on the MemoryDc}
  PatBlt(MemDc, 0, 0,  00,  00, WHITENESS);
  Ellipse(MemDc, 0, 0,  00,  00);
{Copy the MemDc to the Form Canvas}
  BitBlt(Form .Canvas.Handle,
          00,  00,
          00,  00,
         MemDc,
         0, 0,
         SRCCOPY);
{Select the default bitmap back into the memory dc}
  SelectObject(MemDc, OldMemBitmap);
{Note: You can now use the memory bitmap handle with}
{functions such as GetDiBits()}
{Delete the Memory Bitmap}
  DeleteObject(MemBitmap);
{Delete the MemoryDc}
  DeleteDc(MemDc);
end;