Hi Tom, yeah just in case you didn't find the particular one there is a script here for saving a screenshot image at the same time as saving a regular file:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6249.1

Also in the most recent beta there's a new script method that can generate a render to an image object, which can then be saved to disk instead of the clipboard:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6111.4

- Michael

Very cool - thank you !