How to create a polyEdge on poly?

Is there a way to create a polyEdge between two verts on a polygon?
For instance, say I had an eight-sided poly on which the verts numbered in order clockwise and I want to have a visible edge between vtx[5] and vtx[8]. Anyone know how might I go about doing that?

--JeffD

Bump.

No one has any thoughts on this?

--JeffD