Approach for assigning a user to a certain role based on user profile (locative) data

Hi there,

I have my first Drupal site up and just polishing up some of the UX / Business rules elements of the site.

I need to be able to assign users to ttwo different roles based on their user:location_country attribute.
If they are from US/Canada - they go to one role, otherwise they go to another role.

I know i have to execute some PHP when the User is created, but i am not sure of the syntax or how to set it up.

Any assistance would be greatly appreciated.

Regards,

Kit