Using Airport Express with ADSL Modem

[jlg84]

Hi all. I just moved to Beijing and our apartment came with an ADSL internet modem to connect us to the net. We have three computers in the house: a MacBookPro and two PC laptops. Back home in the US, where I had a cable modem, I had the modem attached to an AirportExpress, which in turn provided us all with wireless connectivity. Here, however, I am supposed to "dial up" to the ADSL with a password and username, which I can manage (most of the time) when the DSL modem is attached directly to any of the computers. Unfortunately, if I try to connect the modem to the Airport Express, none of the computers can connect to the internet. I am sure there is some simple way to do this, but I am not able to figure it out, and none of the Chinese who are here to help us either understand the problem, speak English well enough to grasp the problem, or are familiar with Airport Express. Can someone help?? Please??!??!