sketch segments projected intersection

Hi, I've been looking for a method to determine the intersection of sketch segments (line,Arc, spline etc)  where the segments either intersect or the projected intersection point. I've used ICurve.IntersectCurve, Moddoc:ClosestDistance etc which don't work for projected, and inserting an actual point can be difficult particularly with projections and splines. Is there any methods that I've missed that will determine intersection points for both true intersections & projected intersections for sketch segments?

SolidworksApi macros