How to use environment variables in CFTRECV or CFTUTIL commands

In a FNAME of a CFTRECV, environment variable can be used using the prefix 'env:'
i.e.: FNAME='%env:MYVAR%\&part_&idf'

When in command line or in a batch file, environment variables can be used in the normal way:
i.e.: CFTUTIL send part=PART1, idf=MYIDF, FNAME='%CFTDIRHOME%\pub\myfile'