Along with the file, there is one more file that is also written in APDL to extract geometry information;
This macro file with the file extension *.mac can be called in the ANSYS log file.
After obtaining three geometry files from ANSYS, Matlab is used to reorganize the geometry information in a form that C-language can handle. The M-file will load the three geometry files: “keypointcoords.txt”, “linekeypoints.txt” and “arealines.txt”.
Running the file in Matlab will generate two output files: “skincoordinates.txt” and “stiffenercoordinates.txt”. These files contain the geometry information for the diaphragm skin and for the stiffener respectively.
This code has a document (181 pages) which describe the algorithm in detail.