Good to hear from you Sue
OK, I understand now - this is similar to our School (course category) role assignment where those involved with that school are allowed to view all courses within that category.
In answer to your question - AFAIK
site level role association ( Administration ► Users ► Permissions ► Assign system roles
) can not be done via csv. If you follow the usual csv upload template specifying the courseid as '1' or the shortname of the site it simply associates that users to the Front Page
role ( Administration ► Front Page ► Front Page roles
) rather than the system role.
I would assign them manually, I hope you don't have too many! Another thing to think about is that non-Administrator system roles are displayed in each course's Participants page
. When you assign the users you can click the 'hidden' checkbox so only those with the View hidden role assignments moodle/role:viewhiddenassigns permission (usually the Teacher type roles) can see them but they will 'crowd' the participants list.
I hope this helps