Add quotes to textbox and move cursor between them

Hi...trying to figure out the best way to add quotation marks to a text box (which is on a sheet, not a userform) then move the cursor back one position between them.

I can add them fine (the line below takes whatever string is already in the textbox, called InstructionsBox, and adds two double quotes to the end:

InstructionsBox = InstructionsBox & Chr(34) & Chr(34)

Now I think I need to set focus back to the textbox and move the cursor back between the quotation marks. The SetFocus method isn't available (though SELECT is), and my sorry attempt at using a send key isn't working either

This seems so simple, but I just can't get it to work... any help is appreciated.