Creating a Workflow to Re-Engage Leads with Clay.com and Instantly

i sent an email sequence to lead list that was pushed from clay.com to instantly, and all mails were sent via instantly. Now that the campaign has finished i want to send out another mail sequence to all the leads that had opened their mails. How can i create that workflow between clay.com and istantly to achieve this. help me with the steps. how ca i map this to the existing clay table considering the instantly campaign has finished