Activities not showing under account

I am trying to get an activity (appointment) to show up under the account that it is assigned to. I am setting the regarding field to an opportunity and assigning a contact to it.

I want to be able to see the activity when I look at activities for :

- Account

- Opportunities

- Contact

I am not seeing anything on how to do this, any help would be greatly appreciated. I am a newbie with MS CRM.

Lou