Yeah, but Dee is saying the goal is to highlight the row of the selected cell "without losing any previous highlighted cells"; that sounds like all that's needed is my one-statement code snippet below. Granted, that's much too simple; it would end up highlighting every row just from scrolling the cursor up and down.

Dee, your sample just shows a highlighted cell; it doesn't illuminate me much. You say my solution "didn't work"—but how did it not work? Did it bomb with a message? Fail to do anything at all? Do something but not what you wanted? What?