This guy seems to think that you simply need to hook up pin 1 and 2 directly to the 1/8" microphone jack:

https://adafruit-playground.com/u/delchi/pages/cb-microphone-for-your-pc-breaker-breaker-any-takers

So if you didn't care about the push-to-talk feature, you could just wire up a 4-pin to 1/8" plug and try that. Dunno if the mic impedance would actually be correct or not.