We are able to do copy and paste functionality in dhtmlxgrid using ctrl-c and ctrl-v. Is it possible to do the same copy and paste functionality using right-click copy and paste?
Do you mean block-selection or API calls such as rowToClipboard|gridToClipboard|etc. ?
In second case you can attach custom context menu ( grid already has all necessary for integration ) and just call necessary API methods for related menu items.
In case of block selection - situation is more complex, you still can use custom context menu , but it may require some code modification ( by default block selection will disappear after any complex action inside grid )
In both cases usage of only custom menu are possible, there is no way to use default browser menu and its options.