Dudes, please... You cannot connect an accesspoint to a wireless modem unless that modem can connect to an access point. You can also not find an access point connected to a LAN port in WLAN settings since there is no WLAN on this vaio. An access point is, and the name sais it all, a point of access. It allows OTHER wireless devices to connect to it, it will then act as a link between these WLAN devices and, if connected, a network or network card. So it is your brother that needs to check if he can connect to your access point and not vice-versa. these chances are however very low.... Since you don't have a WLAN card but only the access point you CANNOT connect to the modem.
Most likely or the modem is already an access point, or it can only accept ad-hoc connections directly to a WLAN card. In both cases you cannot connect to it with the materials bundled with the unit. I hope this clears this out a little bit.
