Can you give me more clear picture :
What is the style or main point can be done in regression test plan for automation process?
For example : for manual test plan I try to answer What should be tested;
than for automation test plan I try to answer How to navigate through the pages and Where verification points should be added?
personally,I don't think there's a difference at the test plan level for manual testing and automated testing. From my experience, we always have one test plan for the whole test activities on a project and we decide which test cases should be run manually and which ones should be automated. All this is documented in the same test plan.
We will create Automation Test Script based on a Manual Test Script, So wherever we are verifying something in Manual test script should be verified in the Automated Script.(Most probably for every step we need to put verifications.)
Suggestion: For Verifications try to avoid GUI check points.