Custom Visitor group based campaign

Hi Team,

I am using a custom cookie-based visitor group for promotion. For a situation like below how to handle that?

1.visitor a group G- campaign gold

2.visitor a group S- campaign silver

3.visitor a group P- campaign platinum

If using below method I will check cookie contains valid data or not. how the campaign is for a specific visitor group?

 public class CookieExistsCriterion : CriterionBase<CookieExistsCriterionSettings>
    {
        public override bool IsMatch(IPrincipal principal, HttpContextBase httpContext)
        {
       return IsValidcookievalue() ;
        }
}

Note: I am not able to add a user in visitor group.

Please help me out.