Can I assign the performer's email to my form's variable?

The case here is ... I want to make a process that:

- The performer wants to get a new email, so he must send the requisition to his Director.

- The Director must approve the requisition and the email will be sent to IT Dept.

- After IT Dept. finished the job, I want to resend the acknowledged email back to the Director.

My question is that, how can I make the Director's Email to be one of my form's variable.

Since the Director and IT Dept. isn't the same user in Joget, I cannot use the #performer.runProcess.email#

just like CRM-sample App.

Thanks for your advice.