CheckBox to limit a data validation list

I am wondering how to go about creating a data validation list that is limited by a Checkbox.

On one worksheet I have a table of the daily sales. Within that table I have data validation on a list of the sales person that gets tied to a sale.

On a second worksheet I have a list of employees that are used in the data validation from the first worksheet. A lot of these employees are no longer active. I want to add checkboxes for each employee to be checked or unchecked if active or not.

I would like these checkbxes to limit which employees show up in the data validation on the first worksheet.

Any suggestions???