Don't know what DSTV is. Google seems to imply it's some sort of television???
For post processors, the general advice is one of these: (1) If it's a simple machine controller, you might be able to use one of the existing post processors to generate the NC files from the Creo NCL files.
(2) You might be able to modify an existing post processor to give you the formatting of G-code you need. This requires a bit more knowledge and maybe some programming of a sort.
(3) You can outsource the development of the G-Code to someone like Austin NC or ask the folks you bought your Creo licenses from and they'll probably have a suggestion as to who can supply you.