Shouldn't be that difficult, if you have a third gen(85+) big red, swap that accessory connector with a cig lighter plug, and either splice on, or get an adapter to change the power cord for the CB to cig lighter. That's how I've ran em in a car before, I mounted a small Midland on the handelbars and light guard, made a metal plate that goes on one of the squares of the rack to mount a small magnetic whip, ran it across the fenders, taped down, to the CB, and went with that. Small is the key here, don't be trying to put a Cobra 29, or a 148 on there. A noise canceling mic, or a PowerMic will really help here. You can also run headphones into your helmet, and connect them to the external speaker port on some. I have a Midland WeatherMax that I've adapted to use my car antennae as a whip, and plug into the power outlet for power. I can literally swap it from car to trike in a matter of seconds.
Just wait, I have a 20" University loudspeaker that I plan on bolting to the front end of my 250es, running that as an external P/A speaker for the CB, and riding around with it on group rides, and at parades.
Although, I've plans of doing the same thing to my bike......
The only problem with using a Midland like mine, is that the power wires all go straight into the radio. Most Cobras have a plug port at the rear, and you can easily swap plugs instead of having to splice.
This is my trike. There are many like it but this one is mine. My trike is my best friend, and it is my life. I must master it as I must master myself. My trike without me is useless. Without my trike, I am useless. I must ride my trike true. My trike and I know that what counts is not the amount of miles we ride, but the time we ride together. My trike is human in it's own ways, therefore I will learn it as my brother. I will learn it's weaknesses, it's strengths, it's parts, and it's soul.