Adding an image to a post

Hello,

Is there a plugin that will add a random image to a post, from a NextGen gallery, that will only add an image if none already exist, and that will not repeat the image until all the images in the gallery have been used once before?

Essentially I’m using rss feeds to populate a site with aggregated content. Some of these feeds/articles have images that are pulled down with the feed and placed in the post. Most do not have images.

Of those that do have images, I don’t want those images replaced. I only want a random image placed on a post if that post does not already have an image.

And, if I have a gallery of 200 images, I don’t want an image to be repeated until all 200 have been used.

I’ve tried “random post to image” – but that pulls from all images, not just a gallery, and duplicates quite often – out of ten posts it used 4 images twice – which doesn’t look good if you’re showing ten posts per page. it also replaces images that are already associated with posts.

Thank you!
Rob