Delete WP post if not thumbnail!

Need a wordpress developer to make a simple plugin: -- Will run daily (using wordpress cron). -- When it tuns , it will go thought all NEW posts, and check a "custom field" in the DB. -- That custom field is leading to a file (hosted on another domain or the same domain). -- If that file (the URL link) gives status 200 OK, then do nothing and move to next post. -- if that file (the URL link) gives status 404 page not found, DELETE the post and move to next post. Basically... I'm trying to delete posts, which are linking to an image... If that image is 404 (not available at that link/location) -- Exclude posts from previous runs: so when you check posts, do not re-check them again next time it runs... instead start checking from posts posted after the last post you checked last time. -- Show me progress if I open the plugin page... something like: 5/201 6/201 7/201 .. deleting 8/201 9/201 etc.. That's all Thanks, Mary