cheat engine script help

hi i need help with cheat engine scripting ya ok so {script1} will change the 5th value to 53 and lets say i has no idea what the 5th value is so later if i wanted to change it back to whatever the fifth value is how do i do that ya liek can you create {script2} with it plz

script 1:
local scan = "04 00 00 00 ?? 55 03"
local replace = "04 00 00 00 53 55 03"
local aob = AOBScan(scan)
if aob ~= nil then
local addr = getAddressList()
local size = (#replace + 1) / 3
for i = 0, aob.Count - 1 do
local mem = addr.createMemoryRecord()
mem.Description = "Address " .. i
mem.Address = aob[i]
mem.Type = vtByteArray
mem.Aob.Size = size
mem.Active = true
mem.Value = replace
end
aob.Destroy()
aob = nil
end