Which programming languages support secp256k1? Which programming languages have some ready libraries that support Bitcoin's ECDSA curve - secp256k1?
The Bouncy Castle project allows for this and it runs on the Java VM (as was mentioned earlier) as well as the .NET Runtime. An example of using it in C# is shown in this blog post. You can use the .NET version from Visual Basic .NET (as well as any of the other languages on the CLR as well, obviously).

For C++, look at the Crypto++ library which supports secp256k1.