Unfortunately, I haven't done what you are trying but I did find a message on a newsgroup that might be helpful:

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&threadm=v9sV8.50886%241D2.23354824%40twister.socal.rr.com&rnum=3&prev=/groups%3Fq%3D%2Bstring%2Bproperty%2Btypeconverter%2Bgroup:microsoft.public.dotnet.*%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26selm%3Dv9sV8.50886%25241D2.23354824%2540twister.socal.rr.com%26rnum%3D3

>Cathi,
>
>It doesn't, but it could. I didn't do that yet because if I did, it would appear in the drop down, but the drop down will also contain all of the other items that implement IControl. I will only have a one (or few) business objects on a form, so it would be nice if the dropdown would display only those. If I could use a TypeConverter (or something) to build a list of all of the objects that are derived from my base business object, that would be great.
>
>bb
>
>>Bill,
>>
>>Does your Business object inherit from Component or implement IComponent?
>>
>>>Hi Cathi,
>>>
>>>The DataSource property that I added is an object type, with simple get{} and set{} that do nothing more than get and set the private field. I didn't set it to type Employee, because I wanted something more generic.
>>>
>>>My goal is to have some code that will read the DataSource and DataMember properties and do the DataBinding automatically.
>>>
>>>The problem comes in setting the property via the property sheet. If I type Employee in the property sheet for the DataSource the resultant code in the Form.cs is
>>>
>>> this.TextBox1.DataSource = "Employee"
>>>
>>>what I would like is
>>> this.TextBox1.DataSource = oEmployee
>>>
>>>I would like to be either to type in the object name and not get the quotes, or have a drop down that shows the available objects. When I used the [TypeConverter("System.ComponentModel.ReferenceConverter")] attribute on the DataSource property, I get a list of all of the components on my form (textbox1, label1, etc). I understand that it is showing all of the controls that implement IControl. I'm trying to do something similar, and I don't know if I have to create my own TypeConverter or not, and if so, how to go about returning the correct value.
>>>
>>>thanks,
>>>bb
>>>
>>>>Hi Bill,
>>>>
>>>>Can you provide some code for the DataSource property? Did you define the data type for the DataSource property to be Employee type?
>>>>
>>>>>Hi Cathi,
>>>>>
>>>>>I was hoping you could help me with this or point me in the right direction. I have created a subclass of the TextBox control in order to add a DataSource and DataMember property. When I set the DataSource property to oEmployee in the property sheet it is written to the code as "oEmployee" (with quotes). I would like to have the object reference (without the quotes) rather than a string. I think I need to the a TypeConverter Attribute, but I'm having trouble getting it to work.
>>>>>
>>>>>thanks,
>>>>>bb