I have a .Net DTO (DataTransferObject) with 24 numeric fields what are editable in a XamDataGrid. When the user changes one of these values i want them to also enter a comment and/or reason for this. My DTO has a string comments field so I'm thinking I need a ControlTemplate that binds to the value of the cell and to the Comments field. I don't want this control template to be visible unless they are editing the value of the cell. Naturally, the width of the cell will have to grow when this ControlTemplate is activated. Could someone please provide a Link where I may see an example of something similar to this...? Thanks in advance. Greg