Using Site General Info attributes in a Criteria

I am planning to have the following scenario:

1 - A user creates a Part Item and assigns one or more sites to it.

2 - The user creates an ECO where, on a Review step, I would like to have a criteria defined where I could drive the Review approver by specifying the Site Country/Area atribute (on the Site General Info tab).

Is there a way to accomplish this?? At the Change Order level I can see that I can use Affected Items.Sites as a Criteria atribute, however the Country/Area atribute is not exposed.

Thanks in advance for your help and best regards,