Ifconfig gets its interface statistics from /proc/net/dev ('cat /proc/net/dev'). The /proc/net/dev key doesn't allow for editing or persistence because the /proc interface is just data that the kernel exports for userland apps to read. That doesn't mean it's not doable but that would mean either a kernel /proc interface change (very likely to happen when pigs fly or Paris runs for office), a change in the ifconfig source to read values from arbitrary sources (write the patch then wait in line to get slagged off on the net-tools developers mailing list for breaking compatibility) or writing a simple "wrapper" that reads values from arbitrary sources under certain conditions (again: compatibility). If you fill in your distribution details in your
LQ UserCP then maybe somebody might be willing to write you such a wrapper. Else maybe start training. Pigs are very intelligent beings and I'm sure they understand your motives :-]