After WordPerfect Office 12 Standard Edition Trial has been installed ...
Open the Quattro Pro (.qpw) file in Quattro Pro 12 by either double-clicking the file or by starting Quattro Pro from the Start Menu.
In Quattro Pro, click File, then click Save As ...
Choose "Microsoft Excel 97/2000/2002/2003" as the file type.
Choose a location to save the file. If I were you, I'd save it in same location as the original Quattro Pro file.
Click the "Save" button.
Now open the Microsoft Excel (.xls) that you just saved in Microsoft Excel as you normally would open any other Microsoft Excel Worksheet.