When you set up a network connection trough the wii's system menu, if there's no internet access the connection can't be used, so if you don't have internet access from your wii you can't use networking features of applications like WiiMC, ftpii, wiiload...So this application, based on the code of fstoolbox for nand access will allow you to enable and set one of the 3 connections as default, meaning you can use networking without internet access.
Warning: this application writes to the nand, it has been tested on my wii without problems, it -should- be as trustable as fstoolbox is.