To answer your original question directly, you can't do it using only Command Prompt. You need to use one of the products provided above using the procedures provided above (or find another alternative - there are probably other options available but this seems like an adequate number to provide as recommendations).
What additional help do you require? We've answered your question. We've provided many ways to accomplish the objective of making a bootable recovery disk even if none were exactly the way you requested because that can't be done (though one that re-installs would have to be obtained from the manufacturer or borrowed from someone with a genuine Vista Installation Disk of the same bit-size).
I don't know what else to say.
Good luck!
Lorien - MCSE/MCSA/Network+/A+ --- If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.