Thats how the Vietcong ID changer/Unbanner works...just makes a all new ID# each sec.
Still is is best to just clone the Admins ID# and hope he kicks/bans it!
Your ID changer can't work on Arma except if you know algorithm to modify the id as you want ...
It can and does work in many ways (has from day 1).
As far as 1 way to clone an ID# you first get the ID and work backwards with a modified installer that comes on the disks to get the valid cd-key.
Another way is to just change it in memory (people are playing with that idea now).
Making a random # generator to send "valid looking" ID's every few secs should not NEED much work...and does not REALLY need to be a valid ID#. Look at how the VC Unbanner works and adapt it to ArmA.