Tapered thread mill with single point tool

There are times when we will machine a tapered thread (1/4 NPT example) with a single point tool.  This can be accomplished in our existing CAM system solidcam (most of our users still use).  I am having trouble finding a solution for this to be able to add a taper angle to the helix.  Automatic draft angle of something would work, but I'm not seeing it.  Any advise?