OSX - Appling Policy By User

I have logged a ticket with sophos but thought id ask if anyone else has a work around as sophos say its apple's design fault.

I have created a USB policy (for staff only to be read only with some exceptions to R&W - targeted at one test user for now 'domain\stafflogon') and this works fine on PC and now thin client, but will not work on mac OSX. Sophos have said that PC looks at Domain\user but apple use domain\computername\user so cannot use just domain\user as it doesn't see the computer name.

Their solution was to add all macs for all staff users E.G ma 1\user 1 - mac2\user 1 but surely this is not the only way to apply policies to users?

I have tried creating a user group but the user would still be domain\User etc.

Has anyone else found a way around this?

Thanks