Follow-up question:

This is a rather minor matter, but my .jpg photo, before I run the Exiftool code you provided, appears in Windows Explorer (Windows XP Home) with the proper value in the column Date Picture Taken. After I run the Exiftool code, the Windows Explorer column Date Picture Taken is now blank, even though the proper information appears to be in the new .jpg file.

Is this a bug in Windows Explorer, or is there some way to modify this code so that Windows Explorer shows the proper date/time in Date Picture Taken? I can post the original .jpg and associated .nef files if that will help. Thanks again!