1. Highlight the provided current curve and Lock it...
2. Draw a freeform curve profile similar to the one shown in the illustration below.
3. Click cplane origin
4. Using snap to endpoint click the endpoint on the
curve to set the cplane
5. Copy the the Commandscript below...
! Circle
1.55756,0
r
1.55756
selcurve
sweep1
enter
6. Highlight the perspective view
7. Run the commandscript by clicking the run command script
icon. You end up with a surface similar to the figure below
8. Select all and delete the freeform shape and its
curve
9. Make sure you Reset your cplane back to world origin
top
10. Unlock the provided curve profile