Yes you can. It is recommended that your libraries be using .Net 4
'Leadwerks.Net' Wrapper can be used to access the Leadwerks engine.
(Located HERE)
'LE.Net', is an alternative library, but is only a direct export of the Leadwerks API without events or strongly-typed inheritance.
(Located HERE)
Add either DLL as a reference to your project. VB.Net can call methods from any managed library using the Microsoft's CLR (Common Language Runtime): C#, Visual C++, and even *shudder* F#.
Take any C# example and paste it into this online converter:Developer Tools Converter
Leadwerks is a very flexible engine, extensible for scripting both within code, and within the editor. This all depends on your programming style, and whether you wish to learn Lua (which I'd highly recommend). I tend to use a mix of both.
I have the most experience on the forums when it comes to VB.Net, and will be more than willing to answer any questions you may have.