HPCC-9282 Ensure the correct name for an expression is extracted

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #4360 from ghalliday/issue9282

HPCC-9282 Ensure the correct name for an expression is extracted

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>