There are a couple of options for the wall switch.
Get one of the wall switches which send out X10 commands. Don't set it to the lamp module house/unit code, but instead, set it to the macro's house/unit code. When you wire in the switch, have the load bypass the switch (always 'on').
Get one of the RF wall switches, and like above, set it to the macro's house/unit code. Just leave the regular wall switch you already have, always set 'on'.
Or do a kluge like I did. I wired up an old AC power adapter to an X10 Powerflash. The wall switch turns the AC power adapter (and just the AC power adapter) 'on' and 'off'. The AC power adapter triggers the Powerflash to send out X10 'on' and 'off' codes to the macro.
The macro, in all three cases, based on conditions like time-of-day, will send out the appropriate X10 commands to the lamp modules in the room.