-- Show dialog box
local dialog = finenv.UserValueInput()
dialog.Title = "Move TAB Numbers"
dialog:SetTypes("Number")
dialog:SetDescriptions("Move x strings downwards:")
dialog:SetInitValues(1)
local dlgresult = dialog:Execute()
if not dlgresult then return end
local stringadd = dlgresult[1]

-- Browse through the note entries in the selection:
local tabinstrument = finale.FCFretInstrumentDef()
for entry in eachentrysaved(finenv.Region()) do
    local staffspec = finale.FCCurrentStaffSpec()
    if staffspec:LoadForEntry(entry) and staffspec:IsTablature() then
        if tabinstrument:Load(staffspec.FretInstrumentDefID) then
            for note in each(entry) do
                local mod = finale.FCTablatureNoteMod()
                if mod:LoadAt(note) then
                    -- Calculated the MIDI offset difference between the strings:
                    local originalstring = tabinstrument:GetStringTuning(mod.StringNumber)
                    local otherstring = tabinstrument:GetStringTuning(mod.StringNumber + stringadd)
                    local midioffset = originalstring - otherstring  
                    -- Transpose:
                    local newmidipitch = note:CalcMIDIKey() - midioffset
                    note:SetMIDIKey(newmidipitch)
                    -- Change the string:
                    mod.StringNumber = mod.StringNumber + stringadd
                    -- Save the new string number:
                    mod:Save()
                end
            end
        end    
    end
end