For example in the combustion/coldEngineFoam/freePiston/0/p field the
internalField entry may be obtained from the include/caseSettings dictionary
using either a relative path:
internalField uniform $include/caseSettings!internalField/p;
or an absolute path:
internalField uniform ${$FOAM_CASE/0/include/caseSettings!internalField/p};
in which recursive substitution using ${...} is applied to expand the $FOAM_CASE
environment variable.