Is there a way we can have 'short' extensions set up for transferring within a site?

We have a large number of clinics each who usually only transfer between themselves: Each site has a 3 digit cost center, so for the most part our extensions are always costcenter and then the 'true' extension number.

We sometimes have requests to try and shorten them, but it isn't really an option: Particularly for users who want to have reserved ones like extension 1 or 0.

I did however come up with an idea which might be possible to implement: Site extensions.

The idea is that each user (Or queue, etc) can have an optional site extension: This only has to be unique per site, and should ideally be turned on per site. It doesn't have to be related to the main extension.

When the user wants to transfer, they hit the transfer button, and dial * or # before the extension itself: The * or # tells Ring Central that it should try to use a short extension within the site of the calling phone.

For example, if my extension is 20521 but I have a short extension set to 3, and someone else who is in cost center 205 (same site) wants to transfer to me (say they are using a deskphone so they can't just use contacts) they can hit the transfer button and dial *3 to send to me.