Save Profile Property Info for a specific user.

Hi. I want administrators in my intranet application to be able to create new users and save Profile information (such as FirstName, LastName etc.) without having to login as that user.
I can save profile properties for the currently logged in user like so:
Profile.SetPropertyValue("FirstName", firstName.Text)

But how can an administrator do this for an account they are not logged in as?
Is this even posible ??

Thanks

Tim