Maybe as a DLL?
But - what's so "secret and special" about your code, are you embarrassed by it?
Even if you put your code in a DLL, make sure it's abstract enough for the user. Since no-one wants to route through several layers of classes, declaring objects to be used by other objects, when just calling one function from a single class could have done it.
Code is still nice as a documentation, unless you've documented it well.