To open the Content Browser from a Windows command prompt, even if Autodesk Civil 3D is not currently open.
The location of the Command Prompt application varies from one version of Windows to another. It is most likely to be found either in Programs or on the Accessories menu under Programs.
aeccb "c:\mydocuments\mycontentbrowser library\mystuff\mystuff.atc”
You can also invoke the Content Browser by locating the file aeccb.exe with Windows Explorer then double-clicking it. If you need to access it frequently, you can create a shortcut.