The main purpose of the Command Panel (left part of the screen) in the module is to modify Control panel (right part of the screen) in some way - set property, call a method etc. In order to get the reference to the Control Panel you can use following code in the Command Panel :
ControlPanel ctrlPnl = (ControlPanel)this.NamingContainer.FindControl(this.ControlPanelID);
To some of you this may seem rather obvious, but I had to ask to figure this out. So to all you, mere mortals like me, here is how you do it