Replacing and then stringing multiple DLLs

I'm using VB.net so keep that in mind.

I'm trying to create a program that is highly edible. Users will be able to change multiple things by just replacing the existing dlls. Kind of like a modding ability.

The new DLL shouldn't have to recreate every function though, it should only include the ones that it changes and then hook to the old dll for anything that it doesn't hav开发者_开发百科e. Is there a way to dynamically do this? Reference another dll (like a proxy) through yourself for anything that doesn't exist in its self?

Sorry if that is confusing. If it still confuses people, I'll draw a picture later =)

I'm Sorry, but it must be done this way. I have already set up everything in the manor and told clients (they have already started developing).

Sounds like you want to write a plugin architecture into your application, why re-invent the wheel, take a look at the Managed Extensibility Framework