HMR assistance

I Need to change inbound DNIS that comes in as 3307xxxx, 3317,3327,or 3337, always want to change it to 3317xxxx. (There are others too but this is an example)  I  Need some syntax help with the replacement value as it keeps giving me a parsing error (So I am sure my syntax is wrong)  Here is what I have so Far:

Can anyone tell me what I am doing wrong?

header-rule

                name                                    MatchTo

                header-name                             To

                action                                  none

                comparison-type                         pattern-rule

                msg-type                                request

                methods                                 INVITE

                match-value

                new-value

                element-rule

                        name                                    MatchT0Value

                        parameter-name                          uri-user

                        type                                    uri-user

                        action                                  store

                        match-val-type                          any

                        comparison-type                         pattern-rule

                        match-value                             ^(3)([1-2])([0-3])(7)([0-9]){4}        *** This matches the digits Correctly