can you please rewrite what you're saying?
I am having a very hard time understand what you mean.
I will say this,
when I had my Core Duo (not Core 2 Duo) imac's logic board replaced, when i clicked on "about this mac" the serial number was no longer there (it might have said "not found" or "not recognized")
i think the serial numbers are hardwired into the logic board.
However, even after you change the logic board, the serial number that your mac initially came with is the serial number it will always have (in terms of what you tell apple if you call them up asking for service)
If you're asking how to rip off or fraudulently trick apple, please go away. I know that piracy and/or theft of intellectual property may be more common in less developed countries where income makes it more difficult to purchase legitimate licenses/machines, but that does not make it ok to do so.