I am trying to set up an LAP1142 to hand out DHCP addresses to wireless clients only. Meaning - I would like the AP to act like your typical home wireless router in that you just plug it in and it sets up and devices get an ip address and all traffic goes out through the internet port. For example - I don't want DHCP addresses to be handed out on BVI1 - only the wireless adapter. BVI1 should pick up a DHCP address from a modem and then all wireless traffic goes out through BVI1 to the modem. I hope this makes sense!
If you want wireless users & AP to be on two different subnet, then it is not possible.
If you don't care they being on the same subnet, then you can configure DHCP pool on your AP like in normal IOS. In that case you have two DHCP server (modem & AP) for the same subnet & you need to split the scope range if you want to properly manage it. Hopefully your AP will respond to all your wireless DHCP request faster than the modem & client will get DHCP from that.