HOW do i connect DLINK WDL 2100 AP to a speed touch wilress ADSL modem

i i am sticked in this scenario pl any help:

Scenario :

i have an ADSL speedtouch cm585(i) wirless/ethernet modem.
i have connected the laptop though wireless interface to it and it’s working great.
i have connected a desktop computer to it through ethernet interface and also it’s working.
i have a DLINK WDL 2100 AP access point that is connected by ethernet to the desktop.

i need to connect my desktop to the internet through this access point that will connect it to the ADSL modem.
how do i do this?

the modem have a static IP address: 192.168.1.254 and subnet mask: 255.255.255.0
and it can give ip addresses.