Sounds like you are importing data into a single table when it should really be split between two related tables so that you can get these relationships in place:
Contacts::__pkContactID = Roles::_fkContactID
Roles::__pkRoleID = Documents::_fkRoleID
How you would import that data from your excel files could be simple or complicated depending on how the data is arranged in rows and columns.
For an explanation of the notation that I am using, see the first post of: Common Forum Relationship and Field Notations Explained
Thank you very much for that. I guess that could be the first step to resolving my problem, even though I was already familiar with the notation.
Split the data into to tables and then relate them. I'll look into that.
Again, thank you.