Using Mask Initialization and Parameter with Data Dictionaries

I currently have a system using Model Reference for subsystems and Data Dictionaries to maintain variables. I would like to mask a subsystem and have the Mask Initialization change values of a Constant source block with the value of a struct. I can't get the Mask Initialization to affect any changes on the Constant source block.

All the tutorials show the Initialization changing values in the Model Workspace. How do I get it to affect changes on the values from the Data Dictionary?

[Kausalya Singuru]

You can always set_param to set any properties of the blocks within the masked block. A clear explanation with an example may help in giving you specific solution.