Have a look in the cds.lib in your working directory. My guess is that you have something like:
DEFINE analogLib $CDS_INST_DIR/tools/dfII/etc/cdslib/artist/analogLib
If so, $CDS_INST_DIR is defined as meaning "the installation directory of the software reading the file", which is different for IC and EXT, of course.
You could set it to:
DEFINE analogLib $(inst_root_with:tools/dfII/bin/icfb)/tools/dfII/etc/cdslib/artist/analogLib
DEFINE basic $(inst_root_with:tools/dfII/bin/icfb)/tools/dfII/etc/cdslib/basic
for example. If using IC61, put virtuoso instead of icfb.