Displaying a Regarding Entity Field into SubGrid

Hi!

I'm organizing forms, views and fields in MS CRM 2011 RU5 for a Marina Company. And have a question about it.

Somebody developed before and I re-develop a plug-in to send bulk SMS and Email from MS CRM. To do that I have to create a Campaign first, later on I create a campaignActivity via forms.

On MS CRM forms; I create a campaignActivity(with MarinaUser field) for a Contact. And want to add this MarinaUser field into a subGrid belonging to Contact entity. When I try to add column, I see that campaignActivity entity is seen as Regarding entity for Contact. When I add this column to related subGrid, I can't display the value of MarinaUser.

I wonder if I can display this marinaUser field into Contact Form subGrid? or Is there anything special with this Regarding tag?

Thanks in advance.

Can