If you copy bitcoin 1 to 1 you just have bitcoin , if you don't change the code, its still bitcoin no matter how many times you copy it.
You should just change address formula for example to start from 9 instead 1 or 3 and now you need to modify client for it and people need to use that ur new client etc
Deep technical knowledge is needed here to understand what you are doing. Its above my head a little bit, but if im interested enough i would dig into it.