It turns out that the excel lets you put an image behind the graph and by making the chart area transparent the Board-Off cubic spline drawing functions lets you trace the outline by tweaking the control points for the splines used to make the different section of the board. Here' a couple of examples.
|Brokite - Pop Series 130 x 40 board outline|
|Cabrihna Calibre without the concave tips 133x41cm|
|Half template produced by Board-Off|