Theres not a single dvd writing program that can write coded (css) dvd tracks , so indeed , you have to decrypt the movie first.
If you choose to rip an entire dvd , all the data you need will be in the VIDEO_TS folder. Some decryption tools do not add this particular folder though.
If you fire up Nero (5 or 6 , doesn't matter) and choose the DVD-Movie feature (Disable the wizard , select dvd and select dvd movie) then you will get an explorer-like window with AUDIO_TS and VIDEO_TS folders.
You will only need to drag the contents of your ripped dvd (for instance d:\ripped\coolmovie\unencrypted\video_ts) to the VIDEO_TS folder of nero and let it burn.
Test with a +/- ReWritable first if you're not sure.