Hello, there. I haven't seen your requested expert (DXJ) on JA recently, but I am happy to assist. If she does see this message and is able to help, I'm also happy to opt out. Just didn't want you to be waiting any great length of time.
The Purdue Owl site has some great information about how to do this. Essentially, an executive summary (also called an abstract) is a brief overview of what the reader can expect to see when s/he reads your paper. There should not be a great lot of detail, but imagine having an outline, going through it, and briefly explaining the high points of each topic.
I am also happy to assist with the actual summary should you need me to do that. :)