Design Idea for six-zone four-wire signal switch

Would anyone have a suggestion for the design/construction of a four-wire signal switch (IR signal, RS-485+ signal, RS-485- signal and Ground) that can physically connect and send these existing signals to any one of six independent zones. Each zone has the same four-wires that can recieve the signals. My hope is to control which zones are sent the signals through the use of C or C# code.

I have looked into the possibility of completing with using relays, but the cost is prohibitive and I would think there are more elegant ways to complete.

do your PC have serial /parallel port

The computer has access to both serial port for db9 and usb.

What are you trying to control? IR remote extenders?

I am attempting to add PC control to a six zone household stereo system. Each zone has either a touchscreen or keypad which are hardwired to the system's controller with a RS-485+/-, IR and ground signal wires. I have created an application that mimics the codes necessary to control the system; however some arrangement needs to be implimented to direct which zone the signals are forwarded to.

how you wanna control it? make it clear

Is it a Crestron system? What are the models of the devices, RS485 has addresses.

The system is an existing six-zone home home stereo system, controlled by two three-zone Preamp/Controllers, for a total of six-zones. Each zone has either a keypad or touchpad which is homewired to the preamp/controller. The preamp/controller has an RJ45 input jack where each zone is connected to, with the corresponding pin assignments:

pin 1 - Zone One IR;
pin 2 - Zone Two IR;
pin 3 - Zone Three IR;
Pin 4 - RS485+;
Pin 5 - RS485-;
Pin 6 +12 VDC;
Pin 7 - Ground;
Pin 8 - Page Control.

My desire is to control each/all of zones within the household stereo system through a C# program I've started. I believe I can mimic the appropriate control codes which I would like to send to the preamp/controller to control a zone; however I don't think there is a way to programatically designate the selected zone except by physically switching the output to the appropriate zone input wiring.

My hope was to design/create a six zone circuit with the C# application directing the circuit as to which zone to connect and forward the codes. Each zone would have three wires (RS485+, RS485- and IR) with a common ground (total of 18 zones). It appears that the RS485 input on the preamp/controller is not zone specific, and I wonder if that may mean that each zone may not need their own switching for the RS485. I admit that I don't know enough about your RS485 question blueroomelectronics to be able to adequately answer, and apolgize accordingly.

I hope that my question is clearer now. Please let me know if there is anything that I may have left out and I will attempt to answer.

Thanks,
Bill

Brand names? Model numbers?