Can PowerVCR II convert a DAT file from a VCD disk into a MPEG file and then republish it?

Yes. If you have a Video CD (VCD), you can use PowerVCR II to read the DAT video files of the disk and then select them for conversion into MPEG-1 format. For republishing back to VCD, you will need a VCD creator software (Authoring Tools) to create a VCD that can be played on a VCD or DVD player at home.