Acad for 3D

Hi,

Anyone have any hints as to how to draw a chair seat 3D using AutoCAD
where the chair seat like a country chair, is not flat, but has
depression to fit our bottom, something like the 2 photos I just
uploaded into the photos section

http://photos.groups.yahoo.com/group/cad_cam_edm_dro/lst?
&.dir=/&.src=gr&.begin=33&.view=t&.order=&.done=http%
3a//photos.groups.yahoo.com/group/cad_cam_edm_dro/lst%3f%26.dir=/%
26.src=gr%26.view=t

which I named temporary1 and temporary2. They are photo. no 47 and
48, the last 2.

I have thought of perhaps extruding a circular disc along a path,
then use the bottom section to subtract from a flat box, but the
curve will still not fit our nice bottom.

Thanks

Alex