How to UPDATE multiple records from multiple fields

I have a form listing out the five roles on a Board of Directors, where there's a drop-down list populated from a recordset, and each of the five list boxes is set to a specific board member, where the Role is the qualifier. I need to modify this UPDATE so that an admin could click a drop-down (say for President), choose a different member (populated from the recordset), and click update - and all five unique users selected in the form would be updated in the appropriate table. I've got all five list boxes populating properly, but don't know how to loop through all five and set the newly selected members in the Board table. Suggestions?