ansi 16.6.1.1550
<CORE>
looks into the current search-order and tries to find
the name string as the name of a word. Returns its
execution-token or the original-bstring if not found,
along with a flag-like value that is zero if nothing
could be found. Otherwise it will be 1 if the word had
been immediate, -1 otherwise.
reference: p4_find in ../src/core.c:1253, export CO FIND