Latest posts grid page with custom images

Hi

I would like to set up a page which displays the latest blog posts in a grid format, with an excerpt of the post/author, and an image – but I do not want these images to be the Featured Image that is in the post, and I would like to be able to set a custom image to be displayed for each post on the grid summary page.

Is there a way or plugin that would do this? I’ve searched all the forums without a specific solution to this that works unfortunately.