yehuda is right, and I want to add only two things.
1) If you're a mathematica (and Java) expert, you can try to use mouse creating a gui with GUIKit or, if it's too difficult, with SuperWidgetPackage (search for it in internet). But this requires a big effort, because it's not easy to learn (or, more probably, I'm too stupid...).
2) When you apply your transformations, you must consider that if you deform the circle, probably it transform into an ellipse, so you must to use the circle command in this way
Probably, you must also to rotate it (how? :-) ), but all these things depend on your problem...