SAP_WAPI_CREATE_WORKLIST for more users?

[RomyA]

Hello,

A customer has a field for the user and a field for the task, and the goal is to create a worklist for that user with that task. However, now they want to make both fields select-option fields, so you'd get a list of tasks for all the users that have been selected. 

In the code, they are using SAP_WAPI_CREATE_WORKLIST, but it takes as input only one user and one task. I've tried looking at other transactions for whether they might also have a select-option for the user, but I haven't found any yet, and neither have I found a function module similar to SAP_WAPI_CREATE_WORKLIST  but that takes several users and tasks (tasks in the task-list parameter) as input. 

Does anyone have any recommendations for where to look?