Hikashop Custom field > Type> Custom Text

Hi I'm not sure if the pro version will do this hence the pre-sale question.
I have created a Hikashop Custom field > Type > Custom Text in the Orders section.
As a test into the default field of the element I entered:
{source}[[?php echo date ("Y-m-d");?]]{/source}

The checkout page on hikashop shows todays date via the Custom field with no issue, but the value of the custom field doesnt get stored after submission.
Instead the order in the backend shows {source}[[?php echo date ("Y-m-d");?]]{/source} rather than the date.
FYI I also tried
{source}<?php echo date ("Y-m-d");?>{/source}with the same result.
Is there a workaround or is there some setting in the pro system that will allow this to work?
Thanks for any pointers