There is a list of locations to look for macros in conf/defaults.config.
#
# The macro file search path. Each directory in this list is seached
# (in this order) by loadMacros() when it looks for a .pl file.
#
$pg{directories}{macrosPath} = [
".", # search the problem file's directory
$courseDirs{macros},
$pg{directories}{macros},
"$courseDirs{templates}/Library/macros/Union",
"$courseDirs{templates}/Library/macros/Michigan",
"$courseDirs{templates}/Library/macros/CollegeOfIdaho",
"$courseDirs{templates}/Library/macros/FortLewis",
"$courseDirs{templates}/Library/macros/TCNJ",
"$courseDirs{templates}/Library/macros/NAU",
"$courseDirs{templates}/Library/macros/Dartmouth",
"$courseDirs{templates}/Library/macros/WHFreeman",
"$courseDirs{templates}/Library/macros/UMass-Amherst",
"$courseDirs{templates}/Library/macros/PCC",
"$courseDirs{templates}/Library/macros/Alfred",
"$courseDirs{templates}/Library/macros/Wiley",
"$courseDirs{templates}/Library/macros/UBC",
"$courseDirs{templates}/Library/macros/Hope",
];
It appears that the Wiley directory is listed in the standard version of this file.