There are four ways of inserting points into a curve using the Insert Point into Curve dialog.
Click Curve Tools tab > Points panel > Insert to display the Insert Point into Curve dialog.
These options are shown using this curve.
Entering a value of 2.25 and clicking Apply, inserts a point 1/4 of the way between point 2 and point 3.
Entering a value of X - 60, Y - -21, Z - 0 and clicking Apply, inserts this point:
and updates the dialog with the actual coordinates of the point.
Select point 3.
Entering a Distance from current point of 10 and click Apply.
Enter a Number of points of 3.
Select points 2 and 3 and click Apply.