Re-target loading masks?

I'm having a bit of trouble trying to change the loading masks associated with certain components to point to other components.

For example I want to change my grid's loading mask to point to it's parent container, which happens to be a window. This way, whenever the store on the grid reloads, it shows the entire window as being in a load state, rather than just the grid.

Of course all of the windows are dynamically generated, so I need to way (preferably in my controller) to re-target the loading masks associated with the grids, to point to their associated windows.

Does anyone have an example of doing this? I'm been messing with viewConfig and loadMask on the grid but haven't gotten very far.