I have consisted two Bachmann EMD GP40 using MRC throttle.  This allows me to run engines but, but have to use a separate throttle with individual engine address to utilize whistle/horn/light 'F' key functions

I see use of CV19 for consist address, but how do I configure position of unit [front, middle, rear] I see CV21/22 for Consist Function Group but find no explanation of how to use.

How do I configure the consist and have ALL functions controlled by one MRC throttle ??