I had a hard time understanding what you are trying to accomplish. But you can have an employee perform a find and have a button with the replace command to reassign fields to new values. You can also have a Timestamp field that it updated whenever a record is modified and can use the Modified date to search for anything modified in the last week. Maybe you can give some examples with pictures or descriptions of relationships. For example, I can't tell if there is even a relationship or not between employees and customers. Or if employees has anything to do with this process other than the employee loggin in.
FYI, FM 11 and 12 don't play well with each other since they have different file formats. FileMaker made a major change from 11 to 12.