Inbound SIP Manipulation RegEx

Ok, need some help with this rule, hoping you guys can help.

 

I want all inbound calls that start with a +1123456XXXX to ultimately have the all the digits stripped except the last four and I want to add a 1 before sending it on to the local policy.

 

I think I have the match value set correctly but am really unsure of the "new-value"

 

Suggestions welcomed and appreciated!

 

sip-manipulation
        name                           CHANGE-DID-TO-FIVE-DIGIT
        description                    CHANGE-INBOUND-DID-CALL-TO-FIVE-DIGIT-INTERNAL
        split-headers                 
        join-headers                  
        header-rule
                name                           chgURI
                header-name                    request-uri
                action                         manipulate
                comparison-type                pattern-rule
                msg-type                       request
                methods                        INVITE
                match-value                   
                new-value                     
                element-rule
                        name                           SiteAchgURI
                        parameter-name                
                        type                           uri-user
                        action                         manipulate
                        match-val-type                 any