In CST, How do I create a solid starting from an analytical curve?

More precisely, what I am intending to do is: Given a parabolic curve, create a parabolical-cilinder-thing, kind of a cube with a parabolical hollow in one face, but not 3D so you can see the parabolic curve from above and below.
I am afraid I didn't explain myself properly, but anyway, some help please? I am dealing with extrude properties but I am clueless right now. Thank you so much!