We have a macro in myIntercad.myToolkit Utilities/Drawing/Add center marks to all views (id=21). It adds the centermarks rather than centerline however it should help you how you can traverse the view entities and found required ones.
You can download the myIntercad for free at this link: http://intercad.com.au/myintercad/
Artem Taturevych, Application Engineer at Intercad (Australia)
translationXpert – add-in to translate SolidWorks models
myIntercad – an integrated tool for SolidWorks Professionals