Help needed for FomCAM extrusion milling software

Hi!

The business I work for has an old Fom Industrie CNC extrusion mill, but over the years we've lost most of the operating knowledge required to run it.
(It is still used for a few functions where the extrusion being cut is mostly pre-programmed.)

I believe you can import a DXF of a new extrusion profile to cut, but I have no idea how to import this or create a new profile in the program.

Basically, we're trying to mill a rectangular hole in a 100mm DIA aluminium tube, with a 2mm wall thickness.

There is a program already saved for 80mm DIA tubes, however I can't find an option that would let me edit this size (incl. "Variables" which shows the overall extrusion dims).

The issue with trying to use the 80mm DIA saved program on a 100mm DIA pole is that the collet strikes the extrusion, even if we set the cutting depth for an 80mm pole to 0.5mm. (Although I'm sure the max. extrusion height is well above 100mm...)

Any help would be much appreciated! TIA