As stated above your remote sends out only unit codes. You can not do anything to set it to a different house code unless you have the IR543AH. To send different house codes the only way to do it is change the wheel on the IR543. Therefore if you have 2 IR543's sitting on the same table, one set to "A" and one set to "B" and then you send a 1 on from your remote, one IR543 will send out "1A On" and the other "1B ON", they would both do it at the same time so it probably would collide and not work. The IR543AH actually works like getting up turning the dial on the IR543 via IR. To use the AH you must have a PC programmable remote to learn the house code IR commands.

Bill
www.homeautomationnet.com