How to change the Value Help of a date prompt to a calendar display (as in BEx)?

Dear A4O users,

I'm using A4O 1.4 SP9 on top of BO BI 4.0 and BW 7.30.

Does anybody now how I can configure the Value Help of a date prompt?

I prefer to give the users access to a calendar display to pick a date from (as I have in BEx Analyzer).

The field Req Deliv Date (ZEDATU) is referenced to 0DATE in the BW.

I'm still not able to show a calendar display in A4O after changing the BEx general settings on the BW InfoObject or in the BEx Query itself.

Below 2 screenshots of the same BEx Query executed in A4O and in BEx Analyzer.

Image may be NSFW.
Clik here to view.

Image may be NSFW.
Clik here to view.

Thanks in advance for any pointers!