[SR-Users] switch called number

[jaflong jaflong]

Hi Guys

I want to archive this setup

Kamailio to switch called number and the switch to be hidden from the client so there should be no mention of the switched number
in any of the messages back to the client.

for example
phone client calls "alex"
kamailio to switch "alex" to "54321" and send to asterisk
on response from asterisk, kamailio to revert all references to "54321" back to "alex" before send to client

Any suggestions please