Move items from listbox and datagrid

[Jocke]

Hi,

Picture this:

I have two listboxes next to each other. The one to the left lists
available projects. The right one lists selected projects.
Between these two I have two buttons, "Add" and "Remove".

So, you select one project(or more) on the left click the Add-button
and moves the the right listbox. Of course the other way around when
removing projects.
This is a quite common behaviour I guess.

So far I have no problems, BUT:

The listbox to the right must have three columns, ProjectName and two
checkbox columns.
So, you select one project(or more) on the left click the Add-button
and moves the the right listbox and then check/uncheck the checkboxes
and save the page.

As far as I know you can not have columns in a listbox, so I thought I
could have a datagrid to the right instead, including two checkbox
columns. The problem is that I am not that good at datagrids...

How do I select one item in the listbox, converts it to a datagrid item
and adds it to the datagrid?
And the other way around, how do I select a datagrid item, converts it
to a list item and adds it to the listbox?

Or does anyone have another ideas how to solve this?

Can someone please help me out??

Regards
Jocke