Winforms: Change checked value in datagridview checkbox cell based on dialog result

I have a situation here. I have CheckBox column in DataGridView and it is checked by default (when the form loads). Now I have MessageBox for the confirmation that will pop up when someone wants to uncheck CheckBox. So when the DialogResult returns cancel, it should come back to normal state (previous value) and once DialogResult returns OK, it should uncheck. I have tried many cell events which doesn't suit my situation all will fire after cell change its value. I want to trigger snippets before it changes the value.

Thanks in advance.