Surely the simplest transfer method is a direct USB cable connection e.g.
as in URL
Still a lot cheaper than a new external burner.
re. original post - I think the problem is a bit more subtle. DVD shrink / decrypter will rip existing DVD-Videos, and a DVD-ROM is all that is needed. However, if you are creating DVDs from (say) a TV or graphics capture card, then I can see a potential problem, as Nero probably expects to see a DVD burner to use the DVD burning facility.
There may well be virtual DVD drives available on the web, which would fool Nero, but I don't personally know of any.
However, there are other packages like Powerproducer will import mpegs/other dvds etc. and burn to "hard disk". I don't know if they would still expect a burner to be present though - if I get a moment, I'll disable my burner and try it and let you know.
Of course by the time you buy a cable and something like Powerproducer then you probably might as well buy a burner.