Ribbon Workbench sending parameters on adding a "create new" button

Hi, 

I have a requirement to add another button in the associated view of an entity to have the same functionality of the "Add New {0}" but it has to set some field values by default.

I used the Ribbon Workbench and made a copy of the "Add new {0}" button and customized the command so it does the same function now of creating a new record of the entity but I can't find any parameter in the query string to differentiate which button initiated the addNewFromSubGridStandard method.

Do you have any idea how to add a query string parameter or check which button initiated the method inside the new form?