I have a `mx.controls.DataGrid` datagrid on a page, and the requirement I have is that some *cells* on that datagrid be editable dependent upon some condition in the state of the system.

So far as I can tell I can set the entire datagrid to be editable via the `editable` property, or all values in a column via the `DataGridColumn`'s `editable` property, but I don't see a way to set this on the level of an individual cell within the datagrid.

Any suggestions?