Adding a Contact List to an already build Automated Sequence

I built an automated email sequence and added 3 lists of contacts that i have. I now have a 4th contact list but I cant see anywhere that I can add the new list to the 3 already there. Is there an easy way of doing it or do I have to create a new Automated Email and add all lists. Ive been into Edit campaign and can see my 3 existing lists but cnat see any where to add the 4th list. Hope this makes sense to somebody and that you can help me.