A fit point spline already has tangent lines. If you still want to create a new line, you can do so either by - using line command, selecting coincident constraint between line and point, dragging the line until it is tangent to the spline or you can making a line parallel to the pre-existing tangent line and with the help of other constrains, likely achieve the desired result.
Hi
Thanks for posting. I've created a screencast for you to describe different ways to tangent a spline with line.
Click here to watch the screencast
This might help you
Hi,
Is there a reason why you are not uploading a file such as suggested in your last thread on this topic?
günther