This should then be added at the end of the ACAD / ACADISO.PAT used by AutoCAD / Civil3D.
Where can I find ACAD / ACADISO.PAT
Give the command “Options” in AutoCAD to see the settings in AutoCAD. “Support file search path” are settings for the folders in which AutoCAD searches in - for example:
C:\Users\<user name>\appdata\roaming\autodesk\c3d 2016\enu\support
Locate the two files and add the entire contents of GeoSuite.pat at the end of AutoCAD * .pat.
There are instructions on how to configure AutoCAD on the Autodesk website - search on “Install Custom Hatch Pattern”