Get the cheaper Xara Web Designer 9 Premium or its lesser brother (but do check this has the 3D Extrude).

Xara 3D Maker has an extrude but you would have to import your shape an outline EMF/WMF: http://www.xara.com/us/downloads/xara3d/ for Version 7.
Look for free Xara 3d Maker (version 6, but check they are legitimate offers and not malware or stolen.

You could import a vector from Xara WD9 into Xara 3DM as an alternative.

XDPX9 also allows Blends and the 32-bit version can use Effects as well.

Acorn