Convert MTR files to MTZ file

This kind of request comes up periodically, but there never seems to be a solution. Seems that the MTR file (Autocad?) is its own specialized maybe proprietary format, and the MTZ file (Creo) is its own custom format, too. And searching for information about either never provides any information about what is in them or what the file format must be.

If both files are text files, not binary, and I had to do this, I'd probably get a sample of either format, then suffer through developing a means of editing one to make it comply with the other. A good editor, that allows one to define macros or other repetitive reformatting tasks, could be very helpful.