[TYPO3-ttnews] tx_news: extra sorting field in Backend

[Bert Hiddink [BENDOO e-work solutions]]

Hello,

According:

https://docs.typo3.org/typo3cms/extensions/news/DeveloperManual/ExtendNews/ExtendFlexforms/Index.html#selectbox-sort-by

...an extra sorting field can be added to the backend-form like this:

$GLOBALS['TYPO3_CONF_VARS']['EXT']['news']['orderByNews'] .= 
',tx_myext_myfield';

This works, the field showsup in the select of the BE-form BUT the field 
name ('tx_myext_myfield') is also used as the label in the select while 
I would like this to be something like 'My sorting field'

How can I achieve this?
Thanks in advance for any suggestion!

Regards,
Bert