You will need at least an install of Visual C# Express or Visual Basic Express, because they provide the needed tools (RegAsm.exe & GuidGen.exe).
Download the ZIP-File and extract it to the Location of the "SpeedikonCom.dll" (presumably: [Win Vista and 7]:"%CommonProgramFiles(x86)%\Bentley Shared\speedikon\" or [XP]:"%CommonProgramFiles%\Bentley Shared\speedikon\") [From
now on called "DLL Folder"]
Locate the File "Interop.MicroStationDGN" in your Bentley Program Folder and copy it into the DLL Folder.
Dependency to "Interop.MicroStationDGN" was removed.
Open the Visual Studio Shell and navigate to the DLL Folder. For registering the DLL type:
RegAsm SpeedikonObjectModel.dll /tlb:SpeedikonObjectModel.tlb /codebase
Now you can use the Library inside any VBA Macro.
For an short example, look at