Have you tried the built-in post-processer generator?
You can select the machine orientation: Horizontal.
Then define the axis directions and limits.
Normally you'll get standard g-code output and then the FIL file can be modified to output your "wants" in the code.
Moving through the generator will allow to slightly customize some output, what is posted during tool changes, what gets output at the beginning of the code, type of program numbers, what gets output at an M30, etc.
Also, during your PTC software installation, G-Post, which is a post-processor development tool provided by Austin NC, was installed in directories. This directory, sometimes call Post Processor, will contain a PDF of the latest copy of the FIL manual.