"cutting" a non-helical groove in a cylinder

I have a co-worker who has a cylindrical cut he's trying todo. It's helical to a point, then there's a complex geometry at oneend, wrapping around the curvature of the cylinder.

Wrap works fine for getting his profile onto the surface of thecylinder, but if you deboss it, the groove tapers to the bottom.What we need is a contour that emulates a CNC with a fixed endmillplunging directly down into the cylinder's face, while the cylinderrotates around its axis and moves back and forth to create thecomplex geometry.

SolidworksParts And Features