kchval, Welcome to the discussion area!
If your wireless network is created by another AirPort Express (AX), AirPort Extreme base station (AEBS), or Time Capsule you are in luck if the drive has an Ethernet port.
If both wireless devices are 802.11n capable, you can configure the base station creating the network to allow itself to be extended. Then configure the AX to extend the network. This will enable the AX's Ethernet port.
If either of the wireless devices are not 802.11n capable, you can configure the base station creating the network to act as a WDS main base station. Then configure the AX to act as a WDS remote base station. This will enable the AX's Ethernet port.
