The color panel at the left side of DocCommander's window is called the QuickBar. You can place links to your favourite folders onto QuickBar using drag'n'drop. Simply drag the folder you want to place into QuickBar from the File View window (or even from the Windows Desktop or Explorer - indeed from any drag'n'drop source you can imagine!) to QuickBar. A blue mark will show the location of new folder link.
The Quick Bar panel can be scrolled with mouse wheel or by clicking on the small arrows that appears at the bottom (or top) of QuickBar.
You can remove unneeded shortcuts using the Remove command on the context menu. Right-click on the folder shortcut you wish to remove and select Remove in the context menu.