Many-to-Many relationships Appointment Activity

Folks:

I need help with a problem. We have these 2 entities:

• Account
• Strategy

Each Account falls under a specific Strategy/ Strategies.

eg:

           ABC Inc. falls under Strategies Core, Inflation, Tax

           XYZ Inc. falls under Strategies Bonds, Core

          PQR Inc. falls under Strategies Income, Inflation

There is no support for multi-select pick list in CRM so using the solution listed here (crmtipoftheday.com/.../simple-multi-select-lists-in-crm-2013) I was able to create sub-grid (N:N relationship) to add multiple select and it works great.

The next part is that we also want to know when a marketer has a Appointment Activity to list what all strategy / strategies the meeting was about? The Appointment activity does not allow N:N relationship so what will be the other alternative so that I can add multi select to appointment form?

Thanks !