match value in TO and copy to to from

i would like to match a specific sip-uri prefix in the TO and if found replace the value of the URI-USER in the FROM field then replace the prefix with 44 in from also. i tried this but can't seem to get it to work as an in-manipulation on session-agent.

 

match sip:0001211216 in TO and store the uri-user

replace the from uri-user with the stored value

manipulate the new from to remove 0001211216 and replace it with 44

 

any assistamce would be grateful

 

        name                           mapTO2FROM
        description                    map the number used in the TO to the FROM in 1216 calls
        header-rule
                name                           StoreToUser
                header-name                    To