02-08-2016, 03:39 PM
Have a look at the Pivot Wizard from the toolbox (API working similiar). It uses relative positions to set the pivot, but if you look up the source, you'll get the idea to create a method that does this with absolute values. Just turn that method into a toolbox button then.
Alternatively, create the spline at (0,0,0) before adding CP's.
Alternatively, create the spline at (0,0,0) before adding CP's.