Thanks to all the responses.

Eventually I came up with the lookup table approach, sending one character at a time, and of course it works. The display was just too "jerkey" for my tastes.

In all the various scrolling approaches linked to, none of them use a "conventional" scroll on a 4 line LCD, and prohibit the scroll from "wrapping" to line 3.

Disabling the "line wrap" simply is not possible, IMHO.

Ken