[MusoBob]

Originally Posted by Lokasenna

Can't test this right now, but something like:

local keyswitchOctave = reaper.GetExtState("yourScriptName", "keyswitchOctave")
if keyswitchOctave ~= "" then
  GUI.Val("mnu_mode", tonumber(keyswitchOctave)) -- Ext States are always strings
end

reaper.atexit(function()
  local keyswitchOctave = GUI.Val("mnu_mode")
  reaper.SetExtState("yourScriptName", "keyswitchOctave", keyswitchOctave, true)
end)

WOO HOO !! it works great thanks.

And thanks for Script: Lokasenna_Duplicate selected notes diatonically.lua, I got that to work from the region chord name.