GAL restriction to edit only phone number

Hi,

We have a requirement to enable users only to update phone/Mobile Numbers. Users shouldnt be able to modify the address details and they should only be able to enter/modify phone numbers. We are using Exchange 2010, Exchange Control pannel through OWA provides access to modify address and phone number as well but here requirement is to allow only phone number.

Pls suggest if we can customise and restrict users to only add/modify phone number.

Regards

Mahesh

Regards:Mahesh