How to massively enter a value for a flexfield in a task for a list of PW/EMP

Hi team,
our client asks for having the possibility to enter a value in a flexfield we configured in a task in order to massively enter the information for a list of pending worker/employee.

I mean, an User (Performer) need to enter the value "shift grid" for a list of pending worker/employee and they want to be autonomous to manage a HDSL to do it, is it possible something like this?
We considered to do it by using a HDL, however having look at some guidelines, it seems not possible by using both HD and HSDL but just to update a status for a task.