I have been told by my external compliance auditor that my Reg CC policy needs to be enhanced. Does anyone have a complete policy that includes the new check 21 information?

Look in the Banker Store. While there is a cost here, you get a solid and well thought out template and save many hours of editing time for one or more persons. These can be cost effective ways to comply. Just be sure you do what it will say you do. Yes, there are banks who have a policy that says "insert name here" and they have no clue what the policy says they'll do as compared to their practices.