Buttons event in command bar.

Hello local residents.
Help deal with the problem of running my application from Corel draw.
I do this in c # in VSTA.

if (!myadd.loaded)
            {
                app.CommandBars.Add("mybar",
                    Corel.Interop.VGCore.cuiBarPosition.cuiBarFloating,
                    false).Controls.AddCustomButton("button", "helpmessage", 0, false).Visible = true;
            }

How do I add a click event to the button.
Thanks in advance.