Creating an email for an Opportunity Workflow - need additional options in the picklist for Relative

I'm having a difficult time figuring out how to create an email based on the workflow on the Opportunity Page.

We have a field on the Opportunity page called "Project Status".  I want to do a workflow on this field so when the Project Status field is selected to "Active", I would like an email sent to the Opportunity Owner, Marketing Lead, and Lab Lead.

I understand how to create the email notification for the Opportunity Owner. That is good.   However, I cannot figure out how to create the email for the Marketing Lead and Lab Lead.

These fields are on the Opportunity page as look-up window where the user would select a  Marketing Lead  and Lab Lead.  The look-up window for these fields is a user list to include the email address.