numnum - 9:29 pm on Oct 15, 2011 (gmt 0)
Wow, I can't believe how easy that was. I just created a test page and uploaded it into the two different directories, and then created an SSI that states the argument in the form you indicated (and per the Apache2 documentation). It worked the first time! I nearly fell off my chair.
Thank you, thank you, thank you. WebmasterWorld and its able members and moderators are a true godsend.
P.S. Yes, static HTML only, and my ISP has always kept Apache up-to-date.