myEnumProperty=2;//корректный код

public class myTypeConvertor : TypeConverter 
{

   public override bool CanConvertFrom(ITypeDescriptorContext context,  Type sourceType) 
   {
         return true;
   }

   public override object ConvertFrom(ITypeDescriptorContext context,  CultureInfo culture, object value) 
   {
      if (value is string)
      {
          return Enum.Parse(typeof(myEnum), value.ToString());
      }
     if (value is int)
      {
          return myEnum.Capital;
      }
      return base.ConvertFrom(context, culture, value);
   }