Spline in Part Design with Spreadsheet

[MMSN]

Hi all,
I am so impress for the last 0.16 version of Freecad. Congratulations for this big improvement.
Is it feasible to edit splines curves in part Design with Spreadsheet.?
If yes, how to do this,
If No, Is it on the plan of future improvement?
I am attaching a brief sketch that I did for show my question.

Spline in Part Design with Spreadsheet-1.JPG (40.8 KiB) Viewed 1027 times

[MMSN]

Hi All,
I have made an example using points, arc point and rim point plus coincident and tangent constraints. It is more slow method but run.

Example with Arc and tangent constrains.JPG (162.68 KiB) Viewed 978 times

OCC version: 6.8.0.oce-0.17

Example with Arc and tangent constrains-4.JPG (71.55 KiB) Viewed 972 times

OS: Windows Vista
Word size of OS: 32-bit
Word size of FreeCAD: 32-bit
Version: 0.16.6704 (Git)
Build type: Release
Branch: releases/FreeCAD-0-16
Python version: 2.7.8
Qt version: 4.8.6
Coin version: 4.0.0a