How to disable a cell (make it uneditable) in the grid

Hello,
I have a grid, which contains a combo-box style column. I want that when the user checks the combo-box, some cells in that row become uneditable, and, if possible, those cells' color become grayish.

Thanks in advance.

In such a custom use-case you have to trigger BeginCellEdit and cancel it immediately if the conditions are not fulfilled given by the selected comboboxitem. (Hope it was understandable)

Thank you. since I am not so proficient using both autolisp and opendcl, I will plan it for future.