I would not call the button_click event, I would have the button_click event and your ontime code, call the same macro.
sub Commandbutton_1_Click()'This is not the actual event, just for display!!!
Application.OnTime Now + TimeValue("00:00:10") 'I've never used the ontime, so I'm not sure of the structure. I do know there is lots of help about it on this board.
Sub UserForm1_initialize()'Again, not the real event call, just an example