Masquerading incoming caller id as an extension

I want to be able to make it so when I call into my system from my cell phone at 5551234 it will change the caller id to an extension number of 42. I have already setup a feature code so when my employees dial 42, it dials 5551234, but I now just want it to appear to them that I am calling from 42, so that they will get used to that, and stop dialing the 7 digit number. Thanks in advance for your help!

Setup an inbound route win blank DID and your cell phone CID.

Set the destination of the route as the caller ID module

Set the destination of the caller ID module to the ring group or queue you want to alert.