If fewer than 10 authors, want to have first 6 ellipse followed by

Hi, 

I am using Endnote X9. I would like to have an output style where if there are >10 authors, the first 6 authors are shown, followed by an ellipse, then the last author. Currently, in the Output Style setting there is an option for this for >8 authors. Does anyone know if it is possible to change this for >10 authors?

Many thanks for any advice!