For some reason Autodesk left out the Layer Filters Import and Export features in the Layer Manager, in AutoCAD 2009. So here is a way to bring them back when needed.
From support:
"There is a command called CLASSICLAYER. This command should bring you the older Layer Manager with all of the commands. However, to get this to work correctly, we need to modify the Registry slightly. To add the required Windows Registry:
1. On the Start menu (Windows), click Run.
2. In the Run dialog box, enter regedit. Click OK.
3. Find the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R17.2\ACAD-7000:409\Applications\AcLayer\Extensions
4. Double-click the ADT String Value.
5. In the Edit String dialog box, in the Value Data text box, enter AecLayerManagerEx.dll and click OK.
The next time you launch Civil 3D, type CLASSICLAYER. You should now get a new dialog box that has the correct commands. Keep in mind that the “old” civil layer manager will still function as before. You can modify the CUI to add a button or change the Layer Toolbar to launch this Classic Layer Manager instead, although it will not be dockable."
