To use this filter, double-click the SURFCAM.PST file in the Explorer. The file will open in a text editor. Locate the INC Filters section, then the line:
#IncFilter C:\SURFCAM\SURF2000\FILTERS\ArcFltrMx.dll
You will notice the # symbol at the beginning of the line, indicating that this line is a comment only.
Delete the # symbol so that the line is no longer a comment line, and save the file. Then open SURFCAM. When you open the NC Operations Manager, you will see the ArcFltrMx listed.