I have a NEC8100, let me talk about my needs first, I have two extensions on duty (for example: 604, 608), I want these two extensions to form a department group, so as to ensure that the customer's incoming calls will not be busy. After get off work at 17:00 every day, I will transfer to the doorman, and transfer back to the department group at 08:00 the next day. But department groups seem to be unable to CFW. Now my idea is to use virtual extensions. For example, I create a new virtual extension 600, and transfer 600 to (604, 608 this department group) during working hours, and transfer to another extension on duty during off-duty hours. Please ask me How to switch easily? 15-07 : Can Function Keys be switched with one click? Or automatically transfer to a different destination with day and night mode? Thanks.