How to name extensions

Hello,

i want to add extensions like this:

Office 1 has 3 extensions, i want them like:

111-office1 (that means 111 extension/device @office1)
112-office1
113-office1

Office 2 has 4 extensions,

111-office2
112-office2
113-office2
114-office2

It is just like extensions grouping, groups’ names are Office1, Office2, … etc. And each office has their own extensions, 111,112,113 etc.

But now i can only create extensions that all of them have unique extension numbers (111,112,113 etc.)
But i want to create a user group, with a alphanumeric usernames, and each user has its own extensions/divices with unique numbers only (only unique in the group).

group1
------>111 exten.
------>112 exten.
------>113 exten.

group2
------>111 exten.
------>112 exten.
------>113 exten.

each extensions can logon their divices with a pass and username like this: 111-group1, 113-group2, etc.

Is it possible to do it like this?
I hope that i described my question as well.
Thanks for your help

No that’s not possible.