If you want to load and display a .QRP file (a saved report), you may try the following
code - it's better than nothing. A further problem is that QR2g doesn't want to close
the opened file, so it's not allowed to open again.
QRPreview1.QRPrinter.Cleanup;
QRPreview1.QRPrinter := TQRPrinter.Create;
QRPreview1.QRPrinter.Load(FileName);
QRPreview1.Refresh;