Steve is right. I've done lots of restructuring of houses, and you'd be surprised how much you CAN actually do. BUT I've never done anything like this without a structural engineer's plan. Even then, I have caught structual engineers creating faulty plans because they didn't visit the sight enough etc. and forgot to figure in dynamic loads and just drew a static plan (small wind loads would have blown over the restructured house if I hadn't caught it). They are human and can forget stuff. That is why an experienced contractor is also useful for such structural stuff. Your job is pretty straight forward without too many dynamic loads. One thing is almost sure: that there is (or should be) a footing under your current column and that there isn't one where you want to move it. You probably have to cut out some of the slab where you want to put it and pour an adequate footing, in addition to any other load carrying element changes that the engineer may require.