720 x 352 is an odd size and not one of the supported resolutions in dvd-video specifications. This would have to be reencoded.
DVDLab will not do this unless you have Lab Pro ES version, as it contains an mpeg2 encoder.
You can use AVStoDVD to encode it to 720 x 480. You can even change the output to elementary streams that you can import into DVDLab. Look in the options in AVStoDVD.