Thanks for the kind words 
And nice idea, I’ll be interested to hear how it’ll turn out.
As @Moors7 said, you can do this from outside via USB (serial terminal like PuTTY or CLI), but in order to store the credentials of a non-present WiFi network, you need to know the security cipher (WLAN_CIPHER_AES, WLAN_CIPHER_TKIP or WLAN_CIPHER_AES_TKIP) of your network too and entering a WEP passphrase is not straight forward either (rather change to WPA2 ;-))