Plot a single value on an XY chart

I'm attempting to create a Weight and Balance sheet for my airplane. The need is to plot a dot (or some marker) within a XY chart. The Horizontal axis plots the Moment (which is a value determined by the distance to a point in the airplane from a datum (base) point multiplied by the weight in that location. That's a basis of doing this but not needed as all of those calculations I've done. NOW - I need to plot on a chart where that value lays. It's one dot only and not just a simple scatter chart. On the attached workbook shows what I'm after. The black hyphen/dot I placed there myself as an object. I'd like the dot placed that from the datafield using the values 2,818 and 299. Thanks for your assistance.
David Dressler, Bend, OR

I appreciate your effort and time. It did help although I just used the two values of total weight and total Moment and it came through. Amazing. Thank for your help. I'll send you what I did - with your help if you're interested in seeing what I was after.... D