editable matrix type control with dynamic columns

Hi,

I have a datatable. Which is returned from an sp. This sp can return a datatable with x amount of columns so I can create a datagrid which can display ok

The data looks something like this -

identity   permission1 permission2 permissionx

me1       0                0

so I created a custom datagrid that autogenerated the columns and I added a celltemplate that basically showed a checkbox column.

The problem is I can't edit it. Nothing I do seems to put the changes back into the datatable.

Does anyone know of an editable type matrix control I can get my hands on or an article to point me in the right direction?

I think the likes of Devexpress etc have this type of control but the matrix type controls I have found so far are readonly. 

Thanks in advance.